Deliverability of e-mails? Meet DKIM and DMARC!

Published 29. 9. 2018

There are plenty of abbreviations in the world of email marketing that a common user almost never meets. However, for a marketing manager, they are essential in terms of deliverability of e-mails. Knowing these and using them correctly can also prevent losing a good reputation and leads to domain and brand protection, so that it doesn’t get attacked by spammers and phishers. Let’s briefly talk about what these abbreviations are.



The biggest issue with e-mailing is the fact that each and every sender can use any address even if they do not necessarily own it. There are several systems that help the receiver determine whether the sender has the right to use the particular address or not.

DKIM (Domain Keys Identified Mail) is one of them. This is not a new thing and it has been used by some providers for many years. It is a technology similar to SPF (Sender Policy Framework), however, DKIM has an important benefit. While SPF connects the domain sender with particular IP addresses which can be used for sending mail, DKIM uses an electronic signature which is generated on the sender’s server, but not connected to any IP address. DKIM is only visible by a DKIM header containing an electronic signature generated by the SMTP server sender. It doesn’t demand anything from the end user unlike classical electronic signatures. The user doesn’t even have to think about the expiration of a certificate or the certificate support itself within the e-mail to the client.



DMARC (Domain-based Message Authentication, Reporting, & Conformance) is a specification enabling the connection of two technologies mentioned, SPF and DKIM. It also informs the receiving server of the rules they should apply on the messages from a certain domain. DMARC goes even a little further, not only does it want to exchange the information about rules, but it’s also able to replace and broaden them. SPF can communicate the rules regarding messages from addresses other than the defined IP addresses. DKIM does not say if there has to be a signature or not, it simply enables the possibility to verify the existing signature.

Therefore DMARC calls for both SPF as well as DKIM and determines the rules regarding messages not compliant with the DMARC domain rules. It allows for the rules to be applied only on some messages if desired and it determines what to do with messages which are not compliant (quarantine or refuse). It also defines the feedback methods allowing the domain owner to accept reports regarding how the DMARC rules have been applied upon the messages, how many messages were compliant, and information on the origins and mechanisms failed.


What is the conclusion?

DKIM/DMARC have brought a lot of changes to companies using e-mail marketing. Big freemailing providers such as Gmail, Hotmail, or Yahoo have had rules for refusing e-mails for a long time. It basically has no impact on common users, it only eliminates the risk of someone else pretending to be them. However, it does have a big impact on companies using the popular freemailing services, which is a very bad thing itself.

We can expect all the e-mail service providers to start using DKIM/DMARC in the future, as it is the only way of preventing address abuse as well as limiting spam. Professional marketers need to pay more attention to quality solutions using DKIM and DMARC. Tiny senders should perceive this as an impulse to get their own domains to stop communicating via freemailing addresses, something that they are already being punished for by spam filters.


This text was originally posted by Commerce Media,

 a business partner of eWay-CRM.


The module Marketing in eWay-CRM allows you to send personalized bulk emails to either leads or existing customers in a professional manner.