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

        • Tip of the week #26: Import/ Export calendars in Zoho Calendar.

          Any calendar on the web or calendars that you create in any other calendar application can be imported in to Zoho Calendar. This will help you to add the events from the calendars that you import to your Zoho Calendar. You also have the option to export

        • Removing calendar for zoho email group

          How do I make it so that an email group created in Zoho Mail does NOT have a calendar? I have a couple groups for our phone systems voicemails - one for each department. Voicemail recordings are sent to this groups email address so they have access to

        • Tip of the week #27: Edit personal calendars in Zoho Calendar.

          In Zoho Calendar, the personal calendars you create can be edited to make changes you need to make. Edit a Personal Calendar The following changes can be made to the personal calendar by editing it: Calendar title Calendar color Reminders and Description

        • Tip of the week #28: Show/ hide, enable/ disable and empty/ delete your calendars in Zoho Calendar.

          The popularity of online calendars has soared in recent years. It's used both for personal and professional reasons. Calendars have evolved into an effective productivity tool in our lives, from creating events for birthdays and anniversaries to scheduling

        • Tip of the week #30: Share calendars publicly in Zoho Calendar.

          In Zoho Calendar, calendars that are created under My Calendars can be shared publicly. Making your calendar public allows others to view it. When you need to share your calendar with a larger group, public sharing can help. You can restrict others from

        • Tip of the week #31: Share your personal calendars within organization.

          Keep your Organization members aware of what's happening. In Zoho Calendar, you can share your personal calendar with all the members in your organization using the Share with org option.When you enable org sharing for a particular personal calendar,

        • Tip of the Week #33: Appointment scheduler in Zoho Calendar.

          In Zoho Calendar, you can use the Schedule Appointment option to share your appointment request form with the public, allowing people to fill out the form to request an appointment with you. This form can be embedded on your website or blog. Visitors

        • Tip of the Week #34: Embed Calendars using Zoho Calendar

          You can make your calendars public and visible to the general public by embedding them in your websites/blogs using Zoho Calendar. You can use the embed code to add your own calendars to your website's/ blog's HTML code, and the calendar will appear on

        • Tip of the week #35: Migrate to Zoho Calendar from Google Calendar.

          If you are looking to move your Google Calendar events to Zoho Calendar, never worry about missing out the events from your Google Calendar. You can migrate the events from Google Calendar using the export option and import it to Zoho Calendar and manage

        • Tip of the week #36: Migrate to Zoho Calendar from Outlook Calendar.

          If you've been using Outlook calendar and looking to migrate to Zoho Calendar, you can seamlessly export your calendars from Outlook and import them into Zoho Calendar without losing any events, participants, and the reminders set for each event. To migrate

        • Shared calendar issues and duplications

          Apparently there was a calendar update?  Now when I schedule an event for a team member that has shared his calendar with me, the event makes me the organizer and adds the event to my calendar as well.  Previous to this "update" I would scheduled an event

        • Subscribed Calendar

          Hi i have subscribed to a calendar for Holidays in Canada it shows all the holidays perfectly but every one of them has the word Canada before the rest of the name is there a way to remove that word Canada? It takes up a lot of space in the square on

        • The year that was at Zoho Calendar 2023- Part 1

          Hello, amazing community members! Happy new year from all of us here at Zoho Calendar. As we begin the new year, we'd like to thank each and everyone of our community members for your unwavering support and love that you have shown for Zoho Calendar.

        • Zoho Calendar 2024: A Year in Review

          Hello, community members! Happy new year from all of us here at Zoho Calendar. As we turn the page to a new year, we extend our heartfelt gratitude to every member of our Zoho Calendar community for your continued support and enthusiasm. Your feedback

        • Zoho Calendar not syncing correctly with personal Google Calendar

          Coming to this forum as Zoho Calendar support team is not responding, any more. For the past 8 weeks, I have been having an issue with Zoho Calendar not syncing with my personal Google Calendar correctly. I subscribed to Zoho Calendar iCal in my personal

        • MTA - BAD IP reputation by outlook/hotmail

          Messages to Microsoft email servers are bouncing back due to poor reputation. Message: 4.7.650 The mail server [136.143.188.206] has been temporarily rate limited due to IP reputation. For e-mail delivery information see https://postmaster.live.com (S775)

        • Zeptomail API error 500 internal server error

          Hi Everyone, getting this eror continuously! Can anyone please guide around the same! Zeptomail API error 500 internal server error Best Regards

        • Waiting multiple days to buy credits, causing my website to suffer

          So I own a fairly large website that gets a lot of registered users. I use transmail send activation emails, and also forgot password emails. I sent an email to zoho's presales team when I was only at 4K/10K emails sent, hoping to buy more credits before

        • Follow up

          Hello, I sent a message 2 days ago but I don't receive any response and I cannot find my ticket here. this is the ticket: Your ticket has been created with the ticket ID 68925465 and subject "Fwd: Fishing-alert" looking forward to seeing your response.

        • What's new in TransMail!

          Note: TransMail is now ZeptoMail. Click here to know more. Hello again, everyone! We've recently crossed the 6 months mark of TransMail's launch. In this time post our launch, we have been constantly working on updating our platform and adding new features

        • June 2021 in TransMail!

          Note: TransMail is now ZeptoMail. Click here to know more. Hello again, everyone! Hope you and your loved ones are doing well. If you're doing less than fine, we truly hope that things only get better for you.  We've had a few updates in the past month

        • TransMail has a new name—ZeptoMail!

          Tried navigating to TransMail's community forum but see a different name now? That's because TransMail has a new name. TransMail is now ZeptoMail! As we’ve grown from an internal service used mainly by other Zoho products to an up-and-coming competitor

        • July 2021 in ZeptoMail!

          Note: TransMail is now ZeptoMail. Click here to know more. Hello again, everyone! Hope you and your loved ones are doing well.  We've had a few updates in the past month in ZeptoMail—some new features and some important announcements. Take look at what

        • Send Email From the ZeptoMail BY API

          What is Zeptomail:- Transactional email service with reliable and fast delivery How we can Create a Connection for Zeptomail in Zoho CRM Go to the Setup Click on Connection Enter Connection Details:- Generate Consumer Key & Consumer Secret Using Zoho

        • Customer email on Opencart 3

          When I place an order, 2 emails are sent: 1) administrator 2) to the user The administrator receives a beautiful letter, but the user receives a damaged letter (see screenshot). What could be the problem?

        • [Announcement] Insert image from URL changes in Zoho Writer

          Hi Zoho Writer users! We'd like to let you know that we've changed the behavior of the Insert image from URL option in Zoho Writer for security reasons. Earlier behavior Once you inserted an image URL in a Writer document, the image would be fetched from

        • Dynamic Signature - Record owner

          Hi everyone, I’m using Zoho Writer merge templates from Zoho CRM and have two questions: Owner signature: How can I automatically insert the CRM record owner’s signature in the merged document? I’m not sure where this signature is stored or how to reference

        • Writer sing up problom

          Zoho writer sing up prolom face

        • Unable to copy into a new document

          Whe I create a new Writer doc and attemp to copy and past I get this message. The only way to copy into a document is I duplicate an existing document, erase the text and save it under a different name and then paste the information. Not ideal. Can you

        • [Webinar] Live demos and user Q&A with Zoho Writer product experts

          Join us on June 12, 2025 for live demos based on your use cases and real-world scenarios raised via form. This is also an opportunity to get your questions answered directly by product experts from the Zoho Writer team. Webinar agenda Live demos based

        • Zoho Writer's built-in citation and bibliography generator

          Hey researchers and writers! Do you manually format citations and bibliographies, spending hours jumping between apps and tabs? If so, then check out Zoho Writer's built-in "Citations and Bibliography" feature. Imagine you're writing a thesis on the future

        • Single and group checkboxes in Zoho Writer's fillable forms

          Hey Writer Fam, Are you making the most out of single and group checkboxes in fillable forms in Zoho Writer? Here is a handy tip to optimize your use of checkboxes, both single and group, and enhance your data collection process. Single checkboxes: Single

        • Collaborate efficiently with Zoho Writer's track changes feature

          Hi Zoho Writer Community, Zoho Writer's track changes feature is a simple, built-in solution that helps you and your team work together efficiently. Instead of juggling multiple versions of a document or building up a long email chain of comments, each

        • Zoho Writer's WordPress extensions

          Hey Zoho Writer users! Say goodbye to all your WordPress content publishing woes with Zoho Writer's WordPress extensions. Publish content with all your formatting and images, republish content when you update a document, and more—from a single window

        • Time-saving table hacks

          Hey Zoho Writer Community, Do you find yourself using a lot of tables in your documents? We're here to share some of our time-saving hacks that will help you work more efficiently, organize your data, and make your documents look neat and professional.

        • Automating document approval and signing with Zoho Writer and Zoho Sign

          Hey Zoho Writer Community! Here's another automation tip to make your processes more efficient! Question: Can I send a document for client approval first, then automatically send it for signing with Zoho Sign if they approve? Since it's the same person

        • Customization hacks in Zoho Writer - Part 2

          Hey community, We're back with some more tricks to personalize your documents, save time, and get in the zone when you work in Writer. Check out part 1 of this post if you haven't already. Let's dive right in! Document ruler units Imagine you're creating

        • Simplify your tax calculations with Zoho Writer

          Hello Zoho Writer Community! Tax season can be stressful, but with Zoho Writer, managing your income tax calculations becomes straightforward and efficient. Here’s an example of how you can use the tables and formulae of Zoho Writer to calculate income

        • Enhance document navigation with headings and TOC

          Hey Zoho Writer Community! We're back with some useful features in Zoho Writer that can simplify your document creation and navigation process. Let's dive right in! Check out our video on how to make the most of Zoho Writer's heading and table of contents

        • Use and download in PDF format of Zoho wirter Merge template using deluge

          Hello Zoho Developers. Here is some information about Zoho Writer. Writer is not just another online word processor, it's a powerful tool for editing, collaboration, and publishing. Even with its wide range of features, Writer's pared-down user interface

        • Next Page