Making Email More Secure: Understanding DKIM and SPF

Making Email More Secure: Understanding DKIM and SPF

Imagine you’re sending an important letter to a friend. You write your message, put it in an envelope, and drop it in the mailbox with your address (From Address) and your friend's address (To Address). But what if someone along the way tampers with your letter, changes the contents, or even forges a letter pretending to be you? Your friend might receive a completely different message, or worse, never get it at all.



This is exactly the kind of problem businesses face with email security. Just like traditional letters, emails can be intercepted, modified, or forged. To protect email communication, organizations use two important security measures: DKIM (DomainKeys Identified Mail) and SPF (Sender Policy Framework).
Zylker Techfix encountered a major issue without these security measures : customers weren’t receiving support emails. Some emails bounced back, while others landed in spam folders. Without DKIM and SPF, email providers couldn’t verify whether Zylker’s emails were genuine or forged.

Understanding DKIM

Like official letters have signatures or company seals to prove authenticity, DKIM (DomainKeys Identified Mail) does the same for emails.

DKIM : The Signature Seal for Emails

  • DKIM attaches a cryptographic signature to every email you send.
  • When the recipient’s email service (like Gmail, Outlook, or Yahoo) gets the email, it checks this signature against your company’s domain records.
  • If the signature matches, the email is verified as authentic and delivered safely.
  • If the signature is missing or doesn’t match, the email might get rejected or marked as spam.

Adapting Custom SMTP for Public Domains

Using email forwarding and two-factor authentication, Zylker Techfix used public domains like Microsoft and Google with Zoho SMTP. Configuring DKIM was not the solution in this case; instead, the Custom SMTP setup within Zoho Desk resolved the issue. To further enhance security, they could enable Custom SMTP OAuth for a passwordless configuration.

Why did Zylker Techfix Implement DKIM?

Zylker Techfix used organization-level email addresses from a domain procured through their official website. These addresses were used by different departments. However, they faced email bounces due to authentication failures when sending messages via Zoho’s servers. This disrupted their customer support services, as bounced emails prevented ticket creation.
To resolve this, they enabled DKIM authentication in Zoho Desk. The setup was simple:
  1. Added the DKIM public key as a TXT record in their DNS settings.
  2. Verified the key using the "Verify" option in Zoho Desk.
  3. Ensured all outgoing emails carried the DKIM signature to authenticate email communications.
By enabling DKIM, Zylker Techfix significantly improved email deliverability, reduced email tampering, and prevented spoofing.

Understanding SPF

Now imagine you’re sending the package to your friend through a trusted courier service like FedEx or UPS. If someone tries to deliver a fake package using their branding, the courier service will refuse to accept it.
SPF (Sender Policy Framework) works in the same way—it ensures that only authorized mail servers can send emails on behalf of your domain.

SPF: The "Authorized Courier"

  • SPF acts as a list of trusted email servers that are allowed to send emails from your domain.
  • When an email is received, the recipient's email provider checks whether it came from an authorized server.
  • If the email comes from a trusted source, it is delivered; else it is rejected or marked as spam.

How did Zylker Techfix implement SPF?

Set up SPF by specifying specified email services as their authorized email senders.
To improve security, Zylker Techfix set up SPF records to tell email providers:
"Only emails sent from Authorized email servers should be considered legitimate. If an email comes from another server, don’t trust it!"

The Benefits
Setting up SPF prevented spam, fraudulent emails, and email spoofing while ensuring better email deliverability. 
After implementing DKIM and SPF, email deliverability improved, customers received emails without issues, and communication became more secure and professional.

Final Thoughts for Every Business
Whether you’re a small startup or a large enterprise, email security matters. Without DKIM and SPF, your business risks lost emails, email spoofing or tampered messages. 
Enable DKIM and SPF today!




    Access your files securely from anywhere

        All-in-one knowledge management and training platform for your employees and customers.







                              Zoho Developer Community




                                                    • Desk Community Learning Series


                                                    • Digest


                                                    • Functions


                                                    • Meetups


                                                    • Kbase


                                                    • Resources


                                                    • Glossary


                                                    • Desk Marketplace


                                                    • MVP Corner


                                                    • Word of the Day


                                                    • Ask the Experts



                                                              • Sticky Posts

                                                              • Register for Zoho Desk Beta Community

                                                                With the start of the year, we have decided to take a small step in making the life of our customers a little easier. We now have easy access to all our upcoming features and a faster way to request for beta access. We open betas for some of our features
                                                              • Share your Zoho Desk story with us!

                                                                Tell us how you use Zoho Desk for your business and inspire others with your story. Be it a simple workflow rule that helps you navigate complex processes or a macro that saves your team a lot of time; share it here and help the community learn and grow with shared knowledge. 
                                                              • Tip #1: Learn to pick the right channels

                                                                Mail, live chat, telephony, social media, web forms—there are so many support channels out there. Trying to pick the right channels to offer your customers can get pretty confusing. Emails are most useful when the customer wants to put things on record. However, escalated or complicated issues should not be resolved over email because it's slow and impersonal.  When you need immediate responses, live chat is more suitable. It's also quick and convenient, so it's the go-to channel for small issues. 
                                                              • Welcome to Zoho Desk Community - Say hello here!

                                                                Hello everyone! Though we have been here for a while, it’s time to formally establish the Zoho Desk Community; we’re really happy to have you all here! This can be the place where you take a moment to introduce yourself to the rest of the community. We’d love to hear all about you, what you do, what company or industry you work for, how you use Zoho Desk and anything else that you will like to share! Here’s a little about me. I am Chinmayee. I have been associated with Zoho since 2014. I joined here
                                                              • Webinar 1: Blueprint for Customer Service

                                                                With the launch of a host of new features in Zoho Desk, we thought it’ll be great to have a few webinars to help our customers make the most of them. We’re starting off with our most talked about feature, Blueprint in Zoho Desk. You can register for the Blueprint webinar here: The webinar will be delivered by our in-house product experts. This is a good opportunity to ask questions to our experts and understand how Blueprint can help you automate your service processes. We look forward to seeing


                                                              Manage your brands on social media



                                                                    Zoho TeamInbox Resources



                                                                        Zoho CRM Plus Resources

                                                                          Zoho Books Resources


                                                                            Zoho Subscriptions Resources

                                                                              Zoho Projects Resources


                                                                                Zoho Sprints Resources


                                                                                  Qntrl Resources


                                                                                    Zoho Creator Resources



                                                                                        Zoho CRM Resources

                                                                                        • CRM Community Learning Series

                                                                                          CRM Community Learning Series


                                                                                        • Kaizen

                                                                                          Kaizen

                                                                                        • Functions

                                                                                          Functions

                                                                                        • Meetups

                                                                                          Meetups

                                                                                        • Kbase

                                                                                          Kbase

                                                                                        • Resources

                                                                                          Resources

                                                                                        • Digest

                                                                                          Digest

                                                                                        • CRM Marketplace

                                                                                          CRM Marketplace

                                                                                        • MVP Corner

                                                                                          MVP Corner









                                                                                            Design. Discuss. Deliver.

                                                                                            Create visually engaging stories with Zoho Show.

                                                                                            Get Started Now


                                                                                              Zoho Show Resources

                                                                                                Zoho Writer

                                                                                                Get Started. Write Away!

                                                                                                Writer is a powerful online word processor, designed for collaborative work.

                                                                                                  Zoho CRM コンテンツ




                                                                                                    Nederlandse Hulpbronnen


                                                                                                        ご検討中の方




                                                                                                                • Recent Topics

                                                                                                                • How to Create a Fixed Sliding Time Window (D-45 to D-15) in Zoho Analytics ?

                                                                                                                  Hello, I would like to create a report in Zoho Analytics based on a sliding time window between D-45 and D-15, with a fixed snapshot of that specific period. The data displayed should strictly reflect activity recorded between D-45 and D-15 only, without
                                                                                                                • How exactly does "Reply assistance" work in Zoho Desk? What context is sent to the LLM?

                                                                                                                  Hi, Im trying to better understand the technical behavior of the feature "Reply assistance" in Zoho Desk, and I couldn’t find detailed information in the current documentation. Specifically, I have questions about what data is actually being sent to the
                                                                                                                • How Does Knowledge Base Search and Article Recommendation Work?

                                                                                                                  Hello, I would like to understand how the Knowledge Base search engine works. Specifically, does it search based on: The article title only? The full article content? Both, the article and the content? Keywords? Tags? Also, how does the system determine
                                                                                                                • View Answer Bot conversations?

                                                                                                                  We are trialing Zia and are experimenting with Answer Bot on our knowledge base. So far so good! Management asks me if it is possible to view Answer Bot conversations, the purpose being to look over its shoulder and confirm that it is working as des
                                                                                                                • Train Zia answer bot on only part of Knowledge Base?

                                                                                                                  We are trialing Zia answer bot and hope to use it on the knowledge base to help our users find the information they are looking for. I have found how to train Zia on the entirety of our knowledge base. But is there a way to train it on only certain categories
                                                                                                                • 🚀 WorkDrive 6.0 (Phase 1): Empowering Teams with Content Intelligence, Automation, Accessibility, and Control

                                                                                                                  Hello, everyone! WorkDrive continues to evolve from a robust file management solution into an intelligent, secure, and connected content collaboration platform for modern businesses. Our goal remains unchanged: to simplify teamwork, strengthen data security,
                                                                                                                • Zoho Campaigns: An Outstanding Email Marketing Tool

                                                                                                                  Introducing Zoho Campaigns! A product designed by Zoho, the Zoho Campaigns is made to create, deliver, and manage integrated email campaigns that can help in boosting the sales of a company and its customer base. Zoho Campaigns is actually an email marketing
                                                                                                                • Zoho Creator Developer Console | Improved Distribution and Lifecycle Management for apps

                                                                                                                  Hello everyone, We're excited to introduce new enhancements now in the Zoho Creator Developer Console. These updates strengthen private app distribution through licensing controls and extend environment support across all installed apps, helping teams
                                                                                                                • Anchor Links in Dashboards

                                                                                                                  Hello,  Our dashboards frequently have multiple sections that would be more easily skipped between using anchor links. Please consider adding an anchor link feature to the text widget? This could be done by adding an anchor link option to the text widget next to the "remove" option (see screenshot). The option would assign an ID to the <div> containing the text widget in the live dashboard. Then, the chosen ID could be linked using a traditional <a href="#link_id"> in the html section of the text
                                                                                                                • Zoho CRM for Everyone's NextGen UI Gets an Upgrade

                                                                                                                  Hello Everyone We've made improvements to Zoho CRM for Everyone's Nextgen UI. These changes are the result of valuable feedback from you where we’ve focused on improving usability, providing wider screen space, and making navigation smoother so everything
                                                                                                                • Sync images with Shopify/Cart

                                                                                                                  Hello, sync images with shopify or other cart, it cuts out the double work of having to upload to shopify/cart and zoho. Thanks
                                                                                                                • Allow selection of select inactive users in User data fields

                                                                                                                  Hello, We sometimes need to select a previous employee that has an inactive account in the User data field. For example, when doing database cleanup and indicating actions are done by a certain employee that weren't filled out when they were part of the
                                                                                                                • Is it Possible to Modify Standard Report Urls

                                                                                                                  Is there a way to permanently modify standard report Urls? Use case: Suppose I have a Products report. Showing list as timeline, calendar, or kanban doesn't make sense. Want to hide that from users by adding #Report:Products?zc_ShowAs=false&zc_Print=false
                                                                                                                • Assessment Answered - Automation (Related List)

                                                                                                                  Hello everyone, We have linked a candidate assessment to our job posting. When someone applies, they are required to answer all the assessment questions. However, some candidates submit their applications without completing the questions. In such cases,
                                                                                                                • Smarter holiday planning with yearly-specific Holiday Lists

                                                                                                                  Hello everyone! Managing holidays and business hours is now easier and more efficient. Holiday Lists now support holidays that fall on different dates every year, while business hours now supports more than one holiday list. This helps businesses manage
                                                                                                                • External User onboarding for zoho connect is not really intuitive.

                                                                                                                  So the external user is sent an invite, which has a button that directs them to login to zoho to view the invite, but if they don't have a zoho account, they cannot access that invite, which seems kinda silly, as there is not real way on for them to create
                                                                                                                • Having trouble fetching contents of Zoho Connect Feeds using the API, requesting alternative API documentation.

                                                                                                                  I'm trying to retrieve feed/post data from Zoho Connect using the API but facing challenges with the current documentation. What I've tried: OAuth authentication is working correctly (getting 200 OK responses) Tested multiple endpoints: /pulse/nativeapi/v2/feeds,
                                                                                                                • How to upload file to Connect using API?

                                                                                                                  Hi there. I looked at the API documentation and nowhere did it mention how to use the API method to upload a file even though it is mentioned that it is possible to be done so. Please help.
                                                                                                                • Select the task view on the board in the Zoho Connect iPhone app

                                                                                                                  Hello. How do I select the task view on the board in the Zoho Connect iPhone app? The Android app has this functionality.
                                                                                                                • The power of workflows in Zoho Marketing Automation - Video Webinar

                                                                                                                  In this Zoho Marketing Automation video webinar, our experts walk you through: Why you may want to create marketing workflows How to create marketing workflows Use Zoho CRM data and apply workflows to automate your marketing strategy How workflows can
                                                                                                                • Auto tagging

                                                                                                                  Some of the articles I enter into Notebook get there when I enter them in Raindrop.io and IFTTT copies the articles in Notebook. When this happens the notes are tagged but instead of useful one word tags with topic the tag pertains to the specific article
                                                                                                                • Constant refresh required in lots of Zoho tabs

                                                                                                                  "Hey Zoho, if you can sync my notification bell across 15 tabs using a BroadcastChannel, why can't you send a 'Data Refresh' signal the same way? We don't need a browser reload—we just need the data to sync without us clicking F5 like it's 1999." "PS:
                                                                                                                • What's New in Zoho Billing | January 2026

                                                                                                                  Excited about the latest enhancements in Zoho Billing? Our January updates bring an intelligent AI assistant, smarter subscription management, and improved tax compliance, saving you time and reducing manual work. Dive into the details below to see how
                                                                                                                • Cliq iOS can't see shared screen

                                                                                                                  Hello, I had this morning a video call with a colleague. She is using Cliq Desktop MacOS and wanted to share her screen with me. I'm on iPad. I noticed, while she shared her screen, I could only see her video, but not the shared screen... Does Cliq iOS is able to display shared screen, or is it somewhere else to be found ? Regards
                                                                                                                • Inserting images into Articles or Knowledgebase

                                                                                                                  Hi, Are there any plans in improving the Knowledgebase text editor so it would allow inserting images through Windows clipboard via copy-paste? Say for example I took a screenshot using the snipping tool in Windows and I'd like to insert that image to
                                                                                                                • Links not functioning in Zoho mail

                                                                                                                  Links that are included in emails I receive are not activating. Nothing at all happens when I click on them. I have researched FAQs and this forum to no avail. Any suggestions?
                                                                                                                • Zoho Mail iOS app update: Manage folders and tags

                                                                                                                  Hello everyone! In the most recent version of the Zoho Mail iOS app, we have brought in support to manage(create, edit and delete) the folders and tags. Create folders Create Tags Edit/ Delete folder In addition to this, we have also brought in support
                                                                                                                • Zoho Social API for generating draft posts from a third-party app ?

                                                                                                                  Hello everyone, I hope you are all well. I have a question regarding Zoho Social. I am developing an application that generates social media posts, and I would like to be able to incorporate a feature that allows saving these posts as drafts in Zoho Social.
                                                                                                                • [Important announcement] Zoho Writer will mandate DKIM configuration for automation users

                                                                                                                  Hi all, Effective Dec. 31, 2024, configuring DKIM for From addresses will be mandatory to send emails via Zoho Writer. DKIM configuration allows recipient email servers to identify your emails as valid and not spam. Emails sent from domains without DKIM
                                                                                                                • Create an Eye-Catching Announcement Widget for Your Help Center

                                                                                                                  Hello Everyone! In this week’s edition, let’s explore how to keep your customers updated with exciting news in the Help Center. See how ZylkerMobile wowed their customers by bringing updates right to their portal. ZylkerMobile, the renowned brand for
                                                                                                                • UI issue with Organize Tabs

                                                                                                                  When looking at the organize Tabs window (bellow) you can see that some tabs are grayed out. there is also a "Add Module/Web Tab" button. When looking at this screen it's clear that the grayed out tabs can not be removed from the portal user's screen
                                                                                                                • Super Admin Logging in as another User

                                                                                                                  How can a Super Admin login as another user. For example, I have a sales rep that is having issues with their Accounts and I want to view their Zoho Account with out having to do a GTM and sharing screens. Moderation Update (8th Aug 2025): We are working
                                                                                                                • Task list flag Internal/External for all phases

                                                                                                                  Phases are commonly used in projects to note milestones in the progression of a project, while task lists can be used to group different types of tasks together. It makes sense to be able to define a task list as either internal or external however the
                                                                                                                • Zoho CRM Feature Requests - SMS and Emails to Custom Modules & Time Zone Form Field

                                                                                                                  TLDR: Add Date/Time/Timezone form field, and be able to turn off auto timezone feature. Allow for Zoho Voices CRM SMS Extension to be able to be added to custom modules, and cases. Create a feature that tracks emails by tracking the email chain, rather
                                                                                                                • Our Review Of Zoho CRM after 60 Days

                                                                                                                  The purpose of this is to just share with Zoho why I love their product, but ultimately why I could not choose Zoho CRM for our next CRM. About two months ago we begun a CRM exploration process for our financial planning firm, based in Texas. We already
                                                                                                                • Link Purchase Order to Deal

                                                                                                                  Zoho Books directly syncs with contacts, vendors and products in Zoho CRM including field mapping. Is there any way to associate vendor purchase orders with deals, so that we can calculate our profit margin for each deal with connected sales invoices
                                                                                                                • Extend the Image Choice Field

                                                                                                                  Hi, The New Yes/No field is great for what it does, and the Image Choice Field is good but could be better with some functions from the Yes/No field. Take an example, rather than just Yes/No you want Yes/No/Maybe (Or more than 3 choices), but unlike the
                                                                                                                • CRM x WorkDrive: File storage for new CRM signups is now powered by WorkDrive

                                                                                                                  Availability Editions: All DCs: All Release plan: Released for new signups in all DCs. It will be enabled for existing users in a phased manner in the upcoming months. Help documentation: Documents in Zoho CRM Manage folders in Documents tab Manage files
                                                                                                                • New 2026 Application Themes

                                                                                                                  Love the new themes - shame you can't get a little more granular with the colours, ie 3 different colours so one for the dropdown menu background. Also, I did have our logo above the application name but it appears you can't change logo placement position
                                                                                                                • Zoho Desk: Macro to assign Ticket to self

                                                                                                                  Hello, We are using macros in Zoho Desk to set some fields and send a response. I would also like to assign the ticket to myself (or whoever applies the macro). I can only set a fixed agent in the macro, so I would have to create one for every agent.
                                                                                                                • Next Page