This article explains why it is important to authenticate your emails.

Email authentication is what differentiates legitimate emails from any spam that would use your domain. A good configuration proves to your recipients that your emails are legitimate and helps to block emails that are not.

Good authentication also allows you to establish your reputation as a sender, helps increase your delivery rates, reduces the risk of having your emails filtered and reported as spam, and increases your recipients' trust in your electronic communications.

Inversely, not authenticating your emails exposes you to risks. If a receiving server cannot prove that a server is entitled to send emails on your behalf, then the following consequences might arise:

  • It will be more difficult to gain, and maintain, a good sender reputation, and your reputation can be easily damaged by a spam campaign that would aim at the reputation of your domain;
  • Your recipients could be informed that the emails “do not seem to come from your domains”, or that the source of the email cannot be confirmed;
  • Your domains could easily be used for phishing campaigns since it is not possible to distinguish legitimate from illegitimate emails.

There are two ways to authenticate emails:

You must know that even if the DKIM signature and the SPF protocol help to prove that an email is legitimate, their absence does not however prove that they are not legitimate.

It is therefore important to implement a DMARC policy to make up for this uncertainty and indicate precisely how to process emails that are not authenticated.