The establishment of a DMARC field limits the misuse of mail and avoid spam, DMARC stands for Domain-Based Message Authentication, Reporting and Conformance and was created to reduce abuse in the use of e-mails. It is based on the famous SPF and DKIM authentication technique. We have already discussed these two techniques in previous articles. Learn now how DMARC can help further increase your deliverability rate.

This set up allows for example to accept the mails having obligatorily a fields spf or dkim, if the mail is not confirmed, then the recipient will receive an automatic message indicating the failure of the sending of mail.

Here is an example syntax of a DMARC field:

v = DMARC1; p = quarantine; pct = 100; rua = mailto: [email protected]; ruf = mailto: [email protected]; adkim = s; aspf = r


Parameter Description
v Protocol version
pct Percentage of messages to filter
ruf Recipient of the forensic report
rua Recipient of the aggregated report
p Procedure with the main domain
sp Procedure with the subdomain
adkim Rule for the DKIM
aspf Rule for the SPF

In order to easily generate a DMARC field, you will be able to use this URL:


DMARC: Increase your deliverability

If you want to increase your deliverability rate, you must, of course, send your newsletters from a whitelisted server … but that’s not all. There are other techniques such as creating an SPF entry or using Sender ID and DKIM. The final step to optimize your e-mail marketing campaigns is the DMARC authentication technique.

As a reminder:

The Sender Policy Framework ( SPF ) works by publishing a record in the DNS zone of your domain, allowing certain authorized IP addresses to send e-mail on behalf of the domain. By synchronizing the IP addresses, it prevents the abuse and particularly the counterfeiting of sender addresses. During synchronization, the domain of the ” Return-Path ” address is considered. Using SPF you can define who is allowed to send e-mails.

The SenderID standard allows you to publish a record in the DNS and authenticate outgoing e-mails. SenderID authenticates e-mail by comparing the IP address of the sender and the IP address of the sender domain owner. For this, we use the domain of the address ” Header From“. The standard Sender ID is used primarily by services like MSN or Hotmail.

With the DKIM (DomainKeys Identified Mail) standard, the e-mail has its own signature, which is compared with the public key by the mail server receiving the e-mail. If the signature and the key coincide, the origin of the e-mail can be verified. It is then apparent that the e-mail has been sent, without being modified, by the sender.

The DMARC standard is based on the SPF and DKIM techniques but broadens these standards. Thus, DMARC specifies how the authentication must take place at the recipient of the e-mail. It is possible to choose which validations must be passed (SPF, DKIM or both).

In addition, the DMARC standard provides a return channel to the sender. Thanks to this return, the latter can evaluate how the recipient uses the e-mail in case the validation has failed. The use of DMARC makes it possible to completely authenticate an e-mail, as soon as the latter passes the validations.

If the email does not pass validations, the owner can be informed of the alleged abuse of his domain.

The standard is used – among others – by Google, AOL, Microsoft and Yahoo, to simplify sender authentication. Google also uses DMARC for the company presentation on Google+.

The advantages of DMARC

Since DMARC is a new authentication tool, the main advantage is the optimization of the deliverability rate in addition to the efforts of the SPF and DKIM standards. Using DMARC reduces Phishing Abuse. In addition, the sender is forced to improve his IP reputation, which can have many benefits for the sender and the recipients. If an IP is used to send e-mails by several senders, these all influence the reputation of the IP and the deliverability rate of it (and therefore of each sender). By using a clean IP address, you reduce this risk.

Another advantage of DMARC and the return channel. This allows recipients to send reports to the issuer, filling gaps in authentication and responding more effectively to abuse.

How to use DMARC to send my newsletters?

SPF is automatically used by Newsletter2Go. Similarly, Sender ID and DKIM records can be published in your account settings. To use DMARC authentication, you must have a dedicated IP address. In addition, for authenticated submission, you must provide a subdomain of the primary domain to build a reputation and publish the necessary records in the DNS. Unlike DKIM, this is mandatory for DMARC.

If you use a dedicated IP at Newsletter2Go, you can contact us to install your DMARC authentication.

The use without dedicated IP is unfortunately not possible for technical reasons.