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!





      Zoho Campaigns Resources


        • 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

          Zoho CRM Plus Resources

            Zoho Books Resources


              Zoho Subscriptions Resources

                Zoho Projects Resources


                  Zoho Sprints Resources


                    Zoho Orchestly Resources


                      Zoho Creator Resources


                        Zoho WorkDrive Resources



                          Zoho CRM Resources

                          • CRM Community Learning Series

                            CRM Community Learning Series


                          • Tips

                            Tips

                          • Functions

                            Functions

                          • Meetups

                            Meetups

                          • Kbase

                            Kbase

                          • Resources

                            Resources

                          • Digest

                            Digest

                          • CRM Marketplace

                            CRM Marketplace

                          • MVP Corner

                            MVP Corner




                            Zoho Writer Writer

                            Get Started. Write Away!

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

                              Zoho CRM コンテンツ




                                ご検討中の方

                                  • Recent Topics

                                  • I wish to upload 40000 Resumes in Zoho Recruit Database. Can I do this in batch of 1000 Resumes ?

                                    I would like to upload thousand or few hundred of resumes in Zoho Recruit in one go. Please let me know how can I do this Or migrate my 40000 resumes from previous ATS to Zoho Recruit.
                                  • Zoho Writer for Proposals

                                    Hi, one of the things we've struggled with since moving to Zoho ecosystem is our proposal software Qwilr does not integrate well. It surprises me Zoho doesn't have proposal software but given all the capabilities of Zoho Writer, I'm wonder if anyone is
                                  • Custom Fonts in Zoho CRM Template Builder

                                    Hi, I am currently creating a new template for our quotes using the Zoho CRM template builder. However, I noticed that there is no option to add custom fonts to the template builder. It would greatly enhance the flexibility and branding capabilities if
                                  • Foutmelding bij uitvoering/opslaan functie 'Left expression is of type TEXT and right expression is of type NUMBER'

                                    Hoi! Ik heb een workflow (zie bijlage) die wordt getriggerd zodra de verwachte weekomzet van een bedrijf wordt aangepast naar een bedrag hoger dan 0. Op dat moment moet een functie (zie bijlage) gaan berekenen wat het benodigde kredietlimiet moet zijn.
                                  • Hoe kun je Nederlandse loonstroken boek in Zoho Books?

                                    Beste Community, Heeft er iemand een idee hoe je standaard loonstroken kunt inboeken in Zoho Books? Ik ben benieuwd hoe jullie dit doen en wat de mogelijkheden zijn.
                                  • Unable to Filter Retail Sales Orders & Need Paid/Unpaid Filter – Zoho Books

                                    Hi Zoho Team, Recently you introduced Retail – Standard and Retail – Premium templates for Sales Orders. However, in the Sales Order module we still cannot filter or segregate Retail Sales Orders separately from normal B2B sales orders. Because of this,
                                  • Service op locatie organiseren met Zoho FSM: waar lopen organisaties tegenaan?

                                    Bij organisaties met service teams op locatie merken we vaak dat de complexiteit niet zozeer in de planning zelf zit, maar in wat er rond die planning gebeurt. Denk aan opvolging na interventies, consistente servicerapporten, en het bijhouden van installaties
                                  • Possible to delete the "Big Deal Alert" in Zoho CRM?

                                    Hi, Is it possible to delete the "Big Deal Alert" in Zoho CRM? My company has no need for it and I want to remove it to clean up my email templates list. Thank you. Moderation Update: Currently, the option to delete the "Big Deal Alert" template is in
                                  • 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
                                  • [Webinar] Top 10 Most Used Zoho Analytics Features in 2025

                                    Zoho Analytics has evolved significantly over the past year. Discover the most widely adopted features in Zoho Analytics in 2025, based on real customer usage patterns, best practices, and high-impact use cases. Learn how leading teams are turning data
                                  • Need advice for product/item search functionality when adding invoices.

                                    My client uses "Catalog or Vendor" name and Product code to search for his items. But Zoho only allow to search by product name and SKU when adding items to Invoices/Estimates. Clients product codes are not unique as they may overlap from different catalogs/vendors.
                                  • 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
                                  • Do buttons and vba msgbox work on mobile, specifially the iPhone zoho sheets app?

                                    In Zoho sheets on the web, I inserted a button and assigned a VBA macro to it. It pops up a msgbox with some text. When I go onto the iPhone mobile zoho sheets app, the button is there. When I click on that button, the spinning asterisk appears for a
                                  • [Webinar] Solving business challenges- Handling the challenge of transitioning to Zoho Writer from legacy tools

                                    Moving to Zoho Writer is a great way to consolidate your business tools and become more agile. With multiple accessibility modes, no-code automation, and extensive integration with business apps and content platforms, Zoho Writer helps solve your organization's
                                  • How can I effectively manage a website with your help?

                                    I’m wondering if it’s possible to develop a custom website with specific features using Zoho as an alternative platform. My goal is to create a website similar to https://tmsim.ph, with the same kind of functionality and user experience. I would truly
                                  • Introducing the Yes/No field: Binary decisions made beautiful

                                    Greetings, form architects! What would you do when you need a simple yes/no answer on your form? Normally, you add a Radio field. Type Yes. Type No. Until now. The new Yes/No field is purpose-built for binary decisions. It is preconfigured, visually consistent,
                                  • Move email between inboxes?

                                    Is it possible to move emails from one team inbox to another? We would like to be able to have a single "catch-all" inbox for incoming requests, and then move the email to the appropriate department inbox. I was hoping we would be able to accomplish this
                                  • 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
                                  • Zoho CRM's sales trend and sales follow-up trend dashboards are now customizable

                                    Dear Customers, We're here with good news! Sales trend and sales follow-up trend are two system-defined dashboards that help you understand trends and anomalies in your sales outreach and conversion efforts. They use Zia's intelligence to identify patterns
                                  • Introducing Rule-Based AI Coding Assistants for Zoho Finance Widgets

                                    Hello customers, We’ve introduced rule-based AI coding assistants to speed up Zoho Finance widget development. You can try them out in Cursor AI and GitHub Copilot. This helps you build widgets quickly using simple prompts, while ensuring the generated
                                  • Marketing Tip #21: Create an About Us page

                                    People don’t just buy products, they buy from brands they trust. An About Us page helps customers understand who you are, what you stand for, and why your business exists. It adds a human touch to your store and reassures shoppers that there’s a real
                                  • Zobot to handle single choice menu when dynamic list content is more than 10 items

                                    Whatsapp supports maximum of only 10 items for its single choice menu. When we need to show a dynamic list with content more than 10, this could be challenging. We essentially need to add a next and previous buton here in order to make it functional.
                                  • Add the ability to Hide Pages in Page Rules

                                    Hi, We have Field Rules to show and hide fields and we have page Rules, but we can't hide a page in Page Rules so it isn't completed before the previous page (And then have the Deny Rules to prevent submitting without both pages completed), we can only
                                  • Column letter from number

                                    Hello, I am trying to select a cell and i have the column number. How do i do this or is there a way of getting the letter from the number? Thank you
                                  • Zoho One Spaces UI

                                    Zoho One も UI が新しくなっていくようです。 Switch Space Overview https://help.zoho.com/portal/en/kb/one/spaces/spaces-ui/articles/swi#Overview Your new space for personalized business productivity https://www.zoho.com/blog/one/your-new-space-for-personalized-business-productivity.html
                                  • Zoho CRM NextGen UI

                                    Zoho CRM の Everyone 画面の UI がまた変わるのですね。NextGen UI 更新日時が1ヶ月前で、Zoho Japan でもアナウンスされていたようですが、気が付きませんでした。 【Zoho CRM】Zoho CRM for EveryoneのUIアップデートのお知らせ https://support.zoho.co.jp/portal/ja/kb/articles/zoho-crm-zoho-crm-for-everyone-s-nextgen-ui-gets-an-upgrade
                                  • 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
                                  • 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
                                  • Temporary Outage in Zoho Cliq Affecting US Users – July 23, 2025

                                    We experienced a service disruption in Zoho Cliq that impacted core functionality for users in the US region. The issue occurred between Jul 23, 2025, 06:54:00 PM IST and 07:13:13 PM IST, lasting approximately 19 minutes. To restore service stability,
                                  • ERROR CODE :550 - 550 5.1.1 Invalid email recipients

                                    This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. mustafa.ashraf@techlink-eg.net, ERROR CODE :550 - 550 5.1.1 Invalid email recipients
                                  • Function #20: Custom calculation in item table of invoices

                                    When you create an invoice in Zoho Books, the 'Amount' of a line item is typically calculated as the product of the "Quantity" and the "Rate" of the item. For instance, if an item has a sales rate of $50 and a quantity of 5 is sold, then the amount would
                                  • Impossible to import Journal from Freshbooks

                                    I have been trying to import journals from Freshbooks since August 30th. Every time I try to import, I get an error message. I have already made sure every row has a date. First it was saying the account and notes had unexpected input and that every debit/credit
                                  • Wie veröffentliche ich ein PDF Datei?

                                    Hallo! Wie veröffentliche ich PDF Datein ich habe ein PDF Datei und den sieht ihr im Upload ich möchte ihn veröffentlichen wie? Mit Freundlichen Grüßen, Herr Bahaa Addin Chkirid
                                  • 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
                                  • Zoho Books emails suddenly going to Spam since 11 Nov 2025 (Gmail + now Outlook) — anyone else?

                                    Hi everyone, We migrated to Zoho Books in July 2025 and everything worked fine until 11 Nov 2025. Since then, Zoho Books system emails are landing in customers’ Spam (first Gmail, and now we’re seeing Outlook/Office 365 also starting to spam them). Impacted
                                  • 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
                                  • 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,
                                  • Next Page