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







                          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 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

                                                                                                          • Zoho Books - France

                                                                                                            L’équipe de Zoho France reçoit régulièrement des questions sur la conformité de ses applications de finances (Zoho Books/ Zoho Invoice) pour le marché français. Voici quelques points pour clarifier la question : Zoho Books est un logiciel de comptabilité
                                                                                                          • Using Zoho Flow to create sales orders from won deal in Zoho CRM

                                                                                                            Hi there, We are using Zoho Flow to create sales orders automatically when a deal is won in Zoho CRM. However, the sales order requires "Product Details" to be passed in "jsonobject", and is resulting in this error: Zoho CRM says "Invalid input for invalid
                                                                                                          • Is Zoho Sheet available for Linux ?

                                                                                                            Is Zoho Sheet available for Linux ?
                                                                                                          • how to disable staff selection Zoho Booking integrated to SalesIQ?

                                                                                                            currently there is only one Consultant in my Zoho Bookings like this I integrate Zoho Bookings into Zoho SalesIQ to create a chatbot. Unfortunately, even though I only have one consultant for a consultation, the user have to pick the consultant. It will
                                                                                                          • Zoho Bookings No Sync with Outlook

                                                                                                            Zoho Bookings appointments are showing on my Outlook Calendar but Outlook events are not showing on Zoho Bookings. How do I fix this?
                                                                                                          • End Date in Zoho Bookings

                                                                                                            When I give my appointments a 30 minutes time I would expect the software not to even show the End Time.  But it actually makes the user pick an End Time.  Did I just miss a setting?  
                                                                                                          • Custom confirmation message

                                                                                                            How can I change the message that users see after they submit the booking form? I have to confirm some details before their appointment is officially "confirmed", so I want to change it where it doesn't say their appointment is "confirmed" but rather
                                                                                                          • Issue showing too many consultations in my workspace link.

                                                                                                            Hi Team, I’ve set up two Workspaces to track meetings from different sources. So far, this has been working well, and the two Workspaces are differentiated without any issues. However, when I navigate to Consultations and share the link to my personal
                                                                                                          • All new Address Field in Zoho CRM: maintain structured and accurate address inputs

                                                                                                            The address field will be available exclusively for IN DC users. We'll keep you updated on the DC-specific rollout soon. It's currently available for all new sign-ups and for existing Zoho CRM orgs which are in the Professional edition. Managing addresses
                                                                                                          • Recurring Supervisor Rule Reminders for Open/In-Progress Tickets

                                                                                                            Hello Zoho Support Team, I would like to suggest a potential improvement regarding reminders for tickets and activities in Zoho Desk. Currently, it is possible to set reminders only once. In the Supervisor Rules section, it is possible to configure reminders
                                                                                                          • Improved RingCentral Integration

                                                                                                            We’d like to request an enhancement to the current RingCentral integration with Zoho. RingCentral now automatically generates call transcripts and AI-based call summaries (AI Notes) for each call, which are extremely helpful for support and sales teams.
                                                                                                          • Deluge sendmail in Zoho Desk schedule can't send email from a verified email address

                                                                                                            I am trying to add a scheduled action with ZDesk using a Deluge function that sends a weekly email to specific ticket client contacts I've already verified the email address for use in ZDesk, but sendmail won't allow it in its "from:" clause. I've attached
                                                                                                          • Zoho Learn & Zoho Connect

                                                                                                            Hi, Is there a way to sync the knowledge base we have in Zoho Learn with the manuals section is Zoho Connect? Thanks,
                                                                                                          • Addin Support in Zoho Sheet

                                                                                                            Is there any addin support available in zoho sheet as like google marketplace to enhance productivity by connecting with other apps, providing AI data analysis, streamlining business processes, and more?
                                                                                                          • Allow syncing Activities from other applications

                                                                                                            Marketing Automation could be a much more powerful platform if you were able to sync activities into the platform (e.g. purchase, donation, etc) outside of a user doing something on your website. I'd love it if you could sync Custom CRM Modules as activities,
                                                                                                          • Changing Corporate Structure - How Best to Adapt Current and Future Zoho Instances

                                                                                                            My current company is Company A LLC with a dba ("doing business as" - essentially an alias) Product Name B. Basically, Company A is the legal entity and Product Name B is what customers see, but it's all one business right now. We currently have a Zoho
                                                                                                          • how to add subform over sigma in the CRM

                                                                                                            my new module don't have any subform available any way to add this from sigma or from the crm
                                                                                                          • {"errors":[{"id":"500","title":"Servlet execution threw an exception"}]}

                                                                                                            Here's the call to move a file to trash. The resource_id is accurate and the file is present. header = Map(); header.put("Accept","application/vnd.api+json"); data = Map(); data_param1 = Map(); att_param1 = Map(); att_param1.put("status",51); data_param1.put("attributes",att_param1);
                                                                                                          • How to Install Zoho Workdrive Desktop Sync for Ubuntu?

                                                                                                            Hi. I am newbie to Linux / Ubuntu. I downloaded a tar.gz file from Workdrive for installing the Workdrive Desktop Sync tool. Can someone give me step by step guide on how to install this on Ubuntu? I am using Ubuntu 19.04. Regards Senthil
                                                                                                          • Integración Books para cumplir la ley Crea y Crece y Ley Antifraude (VeriFactu)

                                                                                                            Hola: En principio, en julio de 2025, entra en vigor la ley Crea y Crece y Ley Antifraude (VeriFactu). ¿Sabéis si Zoho va a cumplir con la ley para cumplir con la facturación electrónica conectada a Hacienda? Gracias
                                                                                                          • How to upload own video?

                                                                                                            How can you upload your own video on your zoho website? I do not want to use another host, but i want to insert my own files. how can i do this?
                                                                                                          • Support new line in CRM Multiline text field display in Zoho Deluge

                                                                                                            Hi brainstrust, We have a Zoho CRM field which is a Muti Line (Small) field. It has data in it that has a carriage return after each line: When I pull that data in via Deluge, it displays as: I'm hoping a way I can change it from: Freehand : ENABLED Chenille
                                                                                                          • A couple of minor enhancements to Workflows

                                                                                                            Last updated on September 17, 2024: These enhancements were initially available for early access, and we've now enabled them for all users. We are elated to announce a couple of enhancements to custom functions in our Workflows! Say hello to: "Source"
                                                                                                          • Announcing new features in Trident for Windows (v.1.32.5.0)

                                                                                                            Hello Community! Trident for Windows just got better! This update includes new features designed to improve and simplify email and calendar management—and it includes a feature you’ve been waiting for. Let’s dive into what’s new! Save emails in EML or
                                                                                                          • How to render either thumbnail_url or preview_url or preview_data_url

                                                                                                            I get 401 Unauthorised when using these urls in the <img> tag src attribute. Guide me on how to use them!
                                                                                                          • Zoho CRM Calendar | Custom Buttons

                                                                                                            I'm working with my sales team to make our scheduling process easier for our team. We primary rely on Zoho CRM calendar to organize our events for our sales team. I was wondering if there is a way to add custom button in the Calendar view on events/meeting
                                                                                                          • Option to Empty Entire Mailbox or Folder in Zoho Mail

                                                                                                            Hello Zoho Mail Team, How are you? We would like to request an enhancement to Zoho Mail that would allow administrators and users to quickly clear out entire folders or mailboxes, including shared mailboxes. Current Limitation: At present, Zoho Mail only
                                                                                                          • Default Sorting on Related Lists

                                                                                                            Is it possible to set the default sorting options on the related lists. For example on the Contact Details view I have related lists for activities, emails, products cases, notes etc... currently: Activities 'created date' newest first Emails - 'created
                                                                                                          • Directly Edit, Filter, and Sort Subforms on the Details Page

                                                                                                            Hello everyone, As you know, subforms allow you to associate multiple line items with a single record, greatly enhancing your data organization. For example, a sales order subform neatly lists all products, their quantities, amounts, and other relevant
                                                                                                          • Create custom rollup summary fields in Zoho CRM

                                                                                                            Hello everyone, In Zoho CRM, rollup summary fields have been essential tools for summarizing data across related records and enabling users to gain quick insights without having to jump across modules. Previously, only predefined summary functions were
                                                                                                          • Create static subforms in Zoho CRM: streamline data entry with pre-defined values

                                                                                                            Last modified on (9 July, 2025): This feature was available in early access and is currently being rolled out to customers in phases. Currently available for users in the the AU, CA, and SA DCs. It will be enabled for the remaining DCs in the next couple
                                                                                                          • Create Lead Button in Zoho CRM Dashboard

                                                                                                            Right now to create Leads in the CRM our team is going into the Lead module, selecting the "Create Lead" button, then building out the lead. Is there anyway to add the "Create Lead" button or some sort of short cut to the Zoho CRM Dashboard to cut out
                                                                                                          • Searching customer field

                                                                                                            Hello, When entering a receipt, we select customer information. The customer information is synced with Zoho CRM. However, we can't find the customer information because it searches for words that begin with the entered value. It needs to search for words
                                                                                                          • Introducing Version-3 APIs - Explore New APIs & Enhancements

                                                                                                            Happy to announce the release of Version 3 (V3) APIs with an easy to use interface, new APIs, and more examples to help you understand and access the APIs better. V3 APIs can be accessed through our new link, where you can explore our complete documentation,
                                                                                                          • stock

                                                                                                            bom/bse : stock details or price =STOCK(C14;"price") not showing issue is #N/A! kindly resolve this problem
                                                                                                          • Rotate an Image in Workdrive Image Editor

                                                                                                            I don't know if I'm just missing something, but my team needs a way to rotate images in Workdrive and save them at that new orientation. For example one of our ground crew members will take photos of job sites vertically (9:16) on his phone and upload
                                                                                                          • Resume Harvester: New Enhancements for Faster Sourcing

                                                                                                            We’re excited to share a set of enhancements to Resume Harvester that make sourcing faster and more flexible. These updates help you cut down on repetitive steps, manage auto searches more efficiently, and review candidate profiles with ease. Why we built
                                                                                                          • WIDGET in related record list ZOHO CRM; how to get and put data to subform custom fields?

                                                                                                            he need: Read and write two custom subform line-item fields on Quotes: Segment_wyceny (picklist/text) and W_pakiecie (number). Write works; read does not return these fields via SDK. Environment Zoho CRM Widget Zoho Embedded App SDK v1.2 Module: Quotes
                                                                                                          • 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
                                                                                                          • Zoho CRM Tracking Google Enhanced Conversions

                                                                                                            Can anyone @Zoho, consultants, or users help me understand if Zoho CRM is going to support Google's Enhanced Conversions? I included some information from Google below about it. We use Google Adwords for our pay per click advertising for lead generation,
                                                                                                          • Next Page