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!




    • 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

    • Recent Topics

    • I want to duplicate a report and name it something else

      Hi, I have created a report, and now want to reproduce it and call it something else. so that I will end up with TWO separate reports with different titles. Please tell me how do I copy / reproduce a report please

    • Zoho CRM: Sales Rep Professional Certification Program on Coursera

      We are happy to share that we have published the Zoho Sales Representative Professional Certificate in partnership with Coursera, a leading platform for online learning and career development that offers access to courses and degrees from leading universities

    • OS X Notebook quits immediately upon launch

      NoteBook for OS X (Sequoia, but also under Sonoma) always quits immediately upon launch (so I cannot use the "Attach user log" option). I've restarted my MacBook but the problem persists. If it helps, attached is a diagnostic report from Library>Log

    • Can External users upload files or images to WorkDrive?

      I want to know if it is possible for someone externally through a link and PW be able to upload files and images onto WorkDrive?

    • Multi-line fields character limits

      Is there a way to set the character limit higher on multi-line fields so that we are not losing information pasted into the field? When the text is entered or pasted, there is no error to say that the text is too large. After saving and going back to view most of the text is gone.   Also, when viewing the resume, the text is not wrapped in the multi line fields and can t be read without scrolling across the page.

    • Taz bot not working — What should I do to resolve this issue?

      I am experiencing issues with the Taz bot in Zoho Cliq—not receiving responses or it does not seem to work as expected. Could you please explain why the Taz bot might not be functioning and what steps I should take to resolve this issue? Thank you!

    • OneNote Migration

      I am trying to migrate two notebooks from OneNote. For five days now I have had no notification that migration has completed and the migration page show 50% complete - one notebook completed one not finished. It just stays like this. I am unable to cancel

    • Set various time slot reminders for task and event

      Hi I would like known if there is possibility to set various time reminders for a task or event like we have the possibility to do in google calendar or google task. For example I'am creating an event or task and I want to be alerted before 30min and

    • Zoho Calendar not functioning---cannot edit, add attendees, etc.

      Hello, My calendar is acting strange. I'm using Chrome as my browser and pop ups are not blocked (the calendar worked fine yesterday). When creating an event, I'm not able to "edit" the event and add attendees, etc. The link is non-responsive. I cannot

    • Spilt Axis for stacked column and line graph

      Each month around this time I prepare a business review deck. One of the biggest annoyances I have with Zoho, also happens to be something that most other platforms have provided for a long time now, and that is being able to create a chart with stacked

    • Pin a note on top

      Dear Zoho Notebook Team, Please highly consider adding ability to pin a note on top and arrange pinned notes. I have a lot of notes that I want to pin important ones on top and this feature is missing badly. Thank you.

    • Windows 11 app ver 2.2.8

      I have been trialing Zoho Notes syncing between my PC and iphone. No problems with iphone but the Windows 64 bit app ver 2.2.8 was very buggy and would lock up completely, needing a Control Alt Delete etc to close it down. It seemed to be connected to

    • Deluge Script: Onboarding → Access Form

      Hello everyone, Edit: Sorry, I think I put this topic in the wrong section. I’ve recently run into an issue that’s been giving me a bit of a headache for the past few weeks. Context: This is my first time using Deluge to create a script, but it’s not

    • Windows Device Authentication

      We have recently started using ManageEngine, and my boss saw a device management feature in the Zoho One directory. We thought it would either help give us more intergration into Zoho one through bringing ManageEngine services through Zoho one. Or, it

    • How can I change spell check language?

      I cannot find the way to change spell check language. My "display language" is English, and I want to have the same one for Spell Check, but it is Russian!!! How can I change it? In one of your explanations you mentioned that I have to choose it from

    • Mail is so slow - doesn't even work!

      Mail has been getting slower and slower - and today it's not even pulling up emails in either Inbox or Unread. This is beyond frustrating since email is a big part of business. Sent a request through the useless help portal - no response. Called the useless

    • User marked as SPAMMER. Mail Fetch has also been disabled for any active POP accounts.

      I am the administrator for joelles.com One of our accounts has been blocked saying this: User marked as SPAMMER. Mail Fetch has also been disabled for any active POP accounts. I cannot change the disabled account in the control panel as it says that it

    • My domain did not activate

      Hi, my domain (apsaindustrial.com.ar) did not activate, and the phone verification message never arrived. Please would you solve this problem? Thanks.

    • ME SALE ESTE ERROR: No fue posible enviar el mensaje;Motivo:554 5.1.8 Email Outgoing Blocked

      Ayuda!! Me sale este error al intentar enviar mensajes desde mi correo electronico de Zoho! Tampoco recibo correos pues cuando me envia rebotan. Ayuda, Me urge enviar unos correo importantes!! Quedo atenta MAGDA HERNANDEZ +5731120888408

    • Is there a way to sync Tags between CRM and Campaigns/Marketing Hub?

      I wonder if there is a way to synch the tags between CRM and Marketing-Hub / Campaigns?

    • how to see if a specific contact opened an email in zoho campaign?

      how to see if a specific contact opened an email in zoho campaign?

    • Revenue Management: #8 Revenue Recognition in Educational & Training Institutions

      Educational Institutions and training centres typically collect course fees at the time of enrolment, sometimes for a one-day workshop and sometimes for a year-long certification course. You might also charge separately for course materials or evaluation.

    • How to Customize Task Creation to Send a Custom Alert Using JavaScript in Zoho CRM?

      Hello Zoho CRM Community, I’m looking to customize Zoho CRM to send a custom alert whenever a task is created. I understand that Zoho CRM supports client scripts using JavaScript, and I would like to leverage this feature to implement the alert functionality.

    • Using files from Zoho CRM in Gemini/ChatGPT/Claude

      Hi all, I’ve got subscriptions to Gemini and a few other AI tools which I use for tasks like data enrichment, email composition, etc. In our workflow, we often receive various documents from clients — such as process workflows, BRDs/requirement documents

    • Maximum file limit in zoho people LMS

      Dear Team, I am having approximately 4.9 GB of material, including PPTs and videos for uploading in zoho people LMS course. May I know what is the maximum limit limit for the course files Thanking you, With regards, Logeswar V Executive _ Operations

    • Dynamically prefill ticket fields

      Hello, I am using Zoho Desk to collect tickets of our clients about orders they placed on our website. I would like to be able to prefill two tickets fields dynamically, in this case a readonly field for the order id, and a hidden field for the seller

    • Optimize your Knowledge Base for better visibility by allowing search engine crawling and indexing

      All you need to know about no-follow and no-index in KB. What are article crawlability and indexability? Crawlability and indexability are vital for making an article visible and accessible to search engines. When a search engine crawls an article, it

    • Has anyone created a public ASAP Guide that I can check out?

      I am thinking of adding an ASAP guide to my web application, but I have noticed that the ASAP widget itself can be really slow to load sometimes. Has anyone created a public ASAP Guide that I can check to see how performant it is? I don't want to spend

    • Zoho Desk Partners with Microsoft's M365 Copilot for seamless customer service experiences

      Hello Zoho Desk users, We are happy to announce that Zoho Desk has partnered with Microsoft's M365 to empower customer service teams with enhanced capabilities and seamless experiences for agents. Microsoft announced their partnership during their keynote

    • What’s New in Zoho Analytics – September 2025

      Hello Users!! In this month’s update, we’re raising the bar across multiple touchpoints, from how you bring in data, plan and track projects to how you design and brand your dashboards. We’ve added the all-new Gantt chart for project visualization, expanded

    • Zoho MCP has no tools for Creator or 3rd Party Apps?

      I don't see a Zoho MCP community forum so putting this here. Two big problems I see: 1) Although Zoho advertises "over 950 3rd party apps" as available through their MCP, when I go to "Add Tools" there are ZERO 3rd party apps available to choose from.

    • Zoho Forms - Zoho Drive connection - Shared Drives not supported

      Hello i am stuck with Google Drive Connection There is no supported shared drives Connection is not support shared drives boolean Query Parameters - supportsAllDrives=true&supportsTeamDrives=true to activate fetch files from the shared drives. Ahat need

    • Can't create package until Bill created?

      I can't understand why we cannot create a package until a Bill is created? We are having to created draft Bills to create a package when the item is received, but we may not have received a Bill from the supplier. Also, Bill # is required, but we normally

    • Whats the Time out Limit for API Calls from Deluge?

      Hi Creator Devs, We are making API calls to third party server via Deluge. Getting this error message: Error at line : 24, The task has been terminated since the API call is taking too long to respond. Please try again after sometime. Whats the default

    • How to get the authorization code for domain transfer from Zoho?

      I have transferred my domain from zoho to godaddy, and that needs a authorization code. I haven't got any mail containing that. How to get the authorization code from domain transfer? Thanks, Arun

    • How can I optimize a Zoho Site page for SEO when embedding external menu or restaurant links?

      Hi everyone, I’m experimenting with building small content hubs on Zoho Sites and want to make sure I’m doing it in an SEO-friendly way. For example, I tried creating a page that highlights restaurant menu items and linked out to a resource like this:

    • Diff signature for compose new email and replies

      Hi,   How do i have different signature for replies and new emails. its inconvenient to have one large signature for replies. Usually on Outlook we have the option to keep separate signatures for new emails and for replies.

    • Zoho Website Site Speed Up & Setting

      We are experiencing slow loading speeds on our Zoho website and would like assistance in optimizing its performance. Kindly review the site and suggest or implement necessary improvements to enhance speed, especially related to: > Caching mechanisms >

    • Clickjacking: Zoho Vault's Response

      Issue: Password manager browser extensions are found to be vulnerable to clickjacking security vulnerabilities that could allow attackers to steal account credentials, TFA codes, and card details under certain conditions. Reported by: Marek Toth, Independent

    • No option for pick up in Zoho Books / Inventory but yes on commerce

      Is it planned to release soon on books/inventory?

    • Next Page