Wednesday, January 1, 2014

Deliverability issues in email marketing

“Even a Billion Dollar scheme is of no use if your email doesn’t land up in the prospect’s inbox”
Yes, that’s true! No matter how effectively we have strategized the offer, no matter how effective is our creativity and content, it holds no stand if we don’t cross the barrier of various filters that are being placed by the ESPs (Email service providers) and the ISPs (Internet service providers). In this blog we will take a closer look at how an email travels from the sender to receiver’s inbox.

What is Deliverability in email marketing?
In simple terms, deliverability means the successful reach/landing/delivery of your email in customer’s inbox. The point or word to be noted in here is “inbox”, the email should get delivered in the inbox and not the spam or junk folder as nobody cares or reads an email that lands up in spam folders (Only ESP monitors it and deletes the content at regular intervals from junk folders).

How an email travels on Internet?

Email Deliverability check
Email Architecture

Step 1
As soon as user hits the submit button, the email is sent from the sender’s inbox via SMTP (Simple Mail Transfer Protocol). This protocol is responsible for the sending part and the receiving part is managed by IMAP or POP3.

Step 2
ESPs check for SPF (Sender Policy Framework) and DKIM (Domain Key Indentified Mail).  SPF is responsible to prevent email spoofing & Spam by verifying the IP address of the sender. SPF allows administrators to specify which hosts are allowed to send mail from a given domain by creating a specific SPF record (or TXT record) in the Domain Name System (DNS).

For example, if Flipkart is sending an email via then Flipkart needs to have SPF verification code embedded on  if the SPF code is absent then ESPs may flag an alert for emails originating from this domain as a spam. DKIM is similar verification process for Domains.

Step 3
Once the ESPs validate the SPF and DKIM of an email, it gets delivered safely in to the inbox of the recipient. If the email fails on this verification then it might land up in the Junk or Spam folder.

How to check the SPF and DKIM in an Email?

Step 1
Click on the “Show original” link in your Gmail inbox.

Email Deliverability check
SPF and DKIM Check - 1

Step 2
Search for Received – SPF: pass and dkim=pass. 

Email Deliverability check
SPF and DKIM Check - 2

If both of the above records are present then you have no reason to worry about the deliverability issues from technical perspective; however there are other issues/concerns which an email marketer faces. We will discuss about them in my next blog. Till then take care and happy new year!


  1. Very interesting and informative. Very well explained, technical terms simplified. Looking forward to read the next blog.

  2. Thanks Ketki and Kadar. Really appreciate your feedback! :)

  3. Good one.... its really nice blog dude...keep it up waiting for your next blog with other ideas...!!!

  4. Informative and Digestive. Well written Mahin. Liked it :)

  5. Mahin..well written n explained.
    actually I m facing same problem in my ecommerce website, even the transactional mails are going in spam coz we are sending as
    now I understood that I ned to have spf verification code in my website...
    it was really helpful..

  6. Diligent...very well explained.
    Wish you a happy writing.
    Stay best..stay blessed.
    Await next instalment Mahin.