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

    • Can't upload attachments.

      I can't upload attachment in Zoho Mail.
    • Empowered Custom Views: Cross-Module Criteria Now Supported in Zoho CRM

      Hello everyone, We’re excited to introduce cross-module criteria support in custom views! Custom views provide personalized perspectives on your data and that you can save for future use. You can share these views with all users or specific individuals
    • Need Guidance on SPF Flattening for Zoho Mail Configuration

      Hi everyone, I'm hoping to get some advice on optimizing my SPF record for a Zoho Mail setup. I use Zoho Mail along with several other Zoho services, and as a result, my current SPF record has grown to include multiple include mechanisms. My Cloudflare
    • How use

      Good morning sir I tried Zoho Mail
    • Zoho Mail Desktop App Not Loading + Can’t Manage Multiple Accounts

      Hi everyone, I’ve been having ongoing issues with the Zoho Mail desktop app for the past few weeks. The app starts to load but gives up midway and never actually opens — there’s no error message, it just stops loading. The main reason I use the desktop
    • 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
    • not able to convert pdf to jpg and other forms and vice versa.

      i want to change my pdf to jpg, word, etc and some times jpg to pdf. i don't know how to do in this.
    • Feature Request: Tag, Search, and Report on Individual Private Comments

      Zoho Desk Team, First, I want to say that we are extensive users of Zoho Desk and it is a core part of our support operations. We rely heavily on the private comments feature for internal communication, knowledge sharing, and maintaining a clear history
    • Quick Create needs Client Script support

      As per the title. We need client scripts to apply at a Quick Create level. We enforce logic on the form to ensure data quality, automate field values, etc. However, all this is lost when a user attempts a "Quick Create". It is disappointing because, from
    • Connecting two modules - phone number

      Hi, I’d like some guidance on setting up an automation in Zoho CRM that links records between the Leads module and a custom module called Customer_Records whenever the phone numbers match. Here’s what I’m trying to achieve: When a new Lead is created
    • Changing an agents email address

      How do you change an agent's email address? I keep getting a red circle even though I am an admin. And on one of my agents he has two email addresses? How is that possible?
    • Creator Change History: Ways to improve

      Hi Everyone, Recently been working in developing this change history(an idea from Zoho Forms) - unlike forms that you can this with a click but using Creator, we can use "old" keyword. The concept I come up with is to put the result in a table however,
    • Attention API Users: Upcoming Support for Renaming System Fields

      Hello all! We are excited to announce an upcoming enhancement in Zoho CRM: support for renaming system-defined fields! Current Behavior Currently, system-defined fields returned by the GET - Fields Metadata API have display_label and field_label properties
    • Error when sending emails from Zoho

      Hello, When trying to send an email from Zoho CRM I keep getting the below error: javax.mail.AuthenticationFailedException: 535 5.7.139 Authentication unsuccessful, the user credentials were incorrect. Any support on this will be much appreciated. Thanks,
    • Zoho Tables is now live in Australia & New Zealand!

      Hey everyone! We’ve got some great news to share — Zoho Tables is now officially available in the Australian Data Center serving users across Australia and New Zealand regions! Yes, it took us a bit longer to get here, but this version of Zoho Tables
    • Zoho Inventory - How to pay a supplier up front then receive multiple deliveries

      How do we manage situations where we pay a supplier up front, then the receive the products in increments? Example Workflow: Create Purchase Order > Receive Bill for full amount > Receive Items 2 or more deliveries. Currently, once a Bill is created against
    • Not all emails from outlook365 migrated to my new zoho account

      I recently setup a new email address hosted by zoho. I migrated all my folders and email from my Outlook365 account to my new zoho account, but not all my emails migrated. Looks like only the past 12 months, or so, made the move. How do I get the rest
    • Zoho Inventory - Composite Items - Assembly - Single Line Item Quantity of One

      Hi Zoho Inventory Team, Please consider relaxing the system rules which prevent an assembly items from consisting of a single line item and outputting a quantity of 1. A client I'm currently working with sells cosmetics and offers testers of their products
    • Clients not receiving emails

      I've been informed that my emails are not being received. Is there anything that I should look into to rectify this? Many thanks!
    • Allocating inventory to specific SO's

      Is there a way that allocate inventory to a specific sales order? For example, let's say we have 90 items in stock. Customer 1 orders 100 items. This allocates all 90 items to their order, and they have a back order for the remaining 10 items which could
    • Max numbr of IMAP Accounts in Zoho Mail?

      In Zoho mail, you can manage the inboxes of other accounts using IMAP (and POP, actually) https://www.zoho.com/mail/help/external-imap-accounts.html Is there a max to the number of inboxes we can add?
    • Formula Fields Trouble

      Hi,  I can't get even a simple formula field to work and must be doing something dumb. This formula: If(Len(Trim(${Quotes.Subject}))=0,1,2) Gives the error: You used the wrong type of data in an argument. Check what you entered between the parentheses of your functions to make sure you put the right kind of data in the right place. This formula: Len(Trim(${Quotes.Subject}))=0 Gives the error: Syntax Error. Check the examples for any functions you're using to see if you formatted them correctly. Make
    • OPTED FOR STORAGE BY DESCRIPTIVE MISGUIDANCE

      We've opened a domain with three mail ids and payment has also been processed now the bill raised is for single use ID with additional storage capacity. Kindly request you to modify the purchase.
    • How can I add a new organization on Zoho Campaign

      I want to create a new organization with my Zoho Campaign
    • White Label certificate

      Hi all, About 72 hours ago, we fulfilled all steps for white labeling (CNAME to point to mail.cs.zohohost.eu), but since then the configuration page is now stuck at "generating certificate" since 3 days. When I execute an NSLOOKUP mail.webfoundry.be it
    • Split my account

      Hello, I recently bought an email service for a friend. But, looks like I used my personal account to buy the plan. Please split the account so that the email service stays in a different account than my personal account.
    • Remote Server is misconfigured

      Dear Team, I am unable to use email id as remote server is misconfigured. It would be really great if you could help on this and get this resolved. Thanks & Regard Rohit Gupta
    • Have Mail Lite, wish to add/purchase 2nd domain and use email

      Hello, I have recently created two new businesses. I have successfully used Zoho to create a domain for one business and have set up two email addresses / users on that domain. I am trying to figure out how to create a second domain, just like I did the
    • Zoho Learn - AI Translate

      Hi Learn team, I had a situation today where I was providing training to a client team and I had written articles into their Zoho Learn to support their learning. I realised that one of the team members was a non-native English speaker and they were struggling
    • Need support in setting up the company email and few other setups

      Need support in setting up the company email and few other setups
    • This mobile number has been marked spam.

      Dear zoho team, I am very happy to use zoho,because it india 🇮🇳 own app, but when we login into zoho account we facing some issue, please solve below issue ASAP. Add your mobile number As an added security measure for Accounts, you need to verify and
    • Add an external email to the allowed list

      I need to allow an external email to raise a ticket on Manage Engine ServiceDesk Plus. The external email is a outside of our domain and is not a domain user. The email address that needs to be allowed to raise a ticket request is noreply@formsatack.com.
    • Display name & account type change

      I made a mistake and subscribed with an individual account instead of business, how can I change the account type and enter the details of the business. The other question, if I can't, then I want the display name of our email to be 'Business name' instead
    • Request to change display name in Zoho mail

      Hello Zoho Mail Support, I am experiencing an issue with changing the display name on my Zoho Mail account. My email address is: info@witchcraftproduction.rs . I have already updated the display name in Settings > Mail Accounts, where it now shows as
    • Outbound IP address SPAM problem.

      Hello Zoho Support, We noticed that one of your outbound IP addresses (136.143.188.12), which delivers our domain’s mail, is currently listed on the UCEProtect blacklist. Because of this, our messages are sometimes flagged as spam by recipient servers.
    • Answer Bot and Personalized Questions

      Hi there, I have the same problem using the SalesIQ Answer Bot and the Zoho Desk Answer Bot (which really need different names, to be honest, in order to avoid confusion...) Customers that visit our website ask questions in the form of "What do you do?"
    • Forwarding

      How can I forward my Zoho account to my gmail account? Noël
    • Your bot just got smarter: AI-Powered routing that reads between the lines

      What if your bot could tell the difference? Between a visitor who just needs a quick answer, someone actively comparing options, and a frustrated customer one click away from leaving? Most bots can't. They deliver the same response to everyone, missing
    • Add a Way to Duplicate Cards in the Same Canvas (Retain All Settings)

      Dear Zoho SalesIQ Team, We would like to request a new feature in Zoho SalesIQ: the ability to duplicate an existing card within the same canvas while retaining all of its information and settings, including conditions, configurations, and display preferences.
    • Zoho Mail CC and BCC not working

      Zoho Mail CC and BCC not working. I have tried multiple combinations amongst my domain aliases but emails sent as CC or BCC never arrive, not even to Spam. I have checked that the DNS is set up correctly in Cloudflare and have even received a DMARC report
    • Next Page