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

    • 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?
    • Accessing Zoho form enteries via API

      Hi As a user I can view enteries to a form at: https://forms.zoho.com/<myOrganisation>/report/<myReportName>/records/web How do I access these entries via API? I don't have any problem with scope and getting tokens. But I have no idea what the API call
    • Blueprint Issue - Being able to set a subform field as mandatory

      I'm creating a blueprint. My record involves a subform which is only shown once field is set but the field gets set in step two of the process. My problem - I can't save the record as the subform field is set to mandatory - If I unset the mandatory field,
    • Blueprint - Mandatory file upload field

      Hi, File upload (as we as image upload) field cannot be set as mandatory during a blueprint transition. Is there a workaround? Setting attachments as mandatory doesn't solve this need as we have no control over which attachments are added, nor can we
    • Zoho Books - Include Quote Status in Workflow Field Triggers

      Hi Zoho Books team, I recently tried to create a Workflow rule based on when a Quote is Accepted by the customer. This is something which I thought would be very easy to do, however I discovered that Status is not listed as a field which can be monitored
    • Zoho Books - Show Related Sales Orders on Quotes

      Hi Books team, I've noticed that the Quotes don't show show the related Sales Order. My feature request is to also show related Sales Orders above the Quote so it's easy to follow the thread of records in the sales and fulfilment process. Below screenshot
    • Add VAT/Tax line to bank adjustments

      When categorising transactions and matching bank feeds with transactions such as customer payments, we use the "Add Adjustment" to add things like fees/bank fees. It would be useful to choose a VAT/Tax rate here. Whilst there is a bank charges option when adding a payment, this goes into the default bank charges account. We use the adjustments so that we can choose the account and separate our fees. We use different card providers and Worldpay charges VAT so we are stuck. We cannot integrate with
    • New Menu Layout Feedback

      I'd really like to see the banking item back on the top of the menu. I'm sure part of it is just because that's what I'm accustomed to. However, for a bookkeeping program, I think there's a logic to having banking be on top. Not a giant issue, but something
    • Form Accessibility

      Hi, is there an update on the accessibility standard of Zoho forms? Are the forms WCAG 2.1 AA compliant? 
    • Cannot schedule report delivery

      The only 'send option' available when exporting reports is 'immediately' The option to schedule the report is missing.
    • adding attachment in sendmail script where attachment is in a CRM field

      Hi all, I have a custom field of type 'File Upload' in one of my modules in my CRM. I want to include the file in that field as an attachment to an email - which is done from a button on  the 'Results' module. I have created a script and a button to initiate an email from that module. The Deluge scripting window has allowed me to add arguments for all the fields I need to use except for the one file upload type field. My script currently looks like the below (content of the email omitted). As you
    • [Free Webinar] Learning Table Series - AI-Enhanced Insurance Claim Management in Zoho Creator

      Hello Everyone! We’re excited to invite you to another edition of Learning Table Series, where we showcase how Zoho Creator empowers industries with innovative and automated solutions. Struggling with lengthy claim processes, a lack of visibility into
    • Not sure how to use credits to my account

      Hi I have a $50 credit to my account. I'm just wondering how I can apply that to either a current invoice or to try a new service. Any advice would be great, thanks. Kind Regards Chris
    • Control who sees Timeline and Interactions in Zoho CRM through Profiles

      The feature has been enabled for all DCs (except US, EU, and IN DCs). We will be rolling it out to the other DCs in the upcoming days. Dear All, In a CRM, not all users would require access to the history of a record. For instance, a Marketing Operations
    • Zoho Desk Integration - Add the option to send the estimate from the Zoho Desk Ticket Integration

      Hi, Currently in the Zoho Desk integration, the user is able to create an estimate from a ticket, once the estimate is created the user can see the estimate under the ticket (see screenshot below), but is not able to send that estimate from Zoho Desk.
    • Utilisation de Zoho en conformité avec l’article 286 du Code général des impôts (CGI)

      Cher(e) client(e), Conformément à l’article 286 du Code général des impôts (CGI) impose aux entreprises assujetties à la TVA d’utiliser des systèmes de caisse ou de gestion commerciale certifiés lorsqu’elles enregistrent des ventes à des particuliers.
    • CRM Validation Rules Support Only Single Condition

      Simply put, CRM validation rules support only a single condition for each field on "All Records". You also cannot specify additional validation rules on the same field because it has already been used in an existing validation rule. The ONLY solution
    • Next Page