DKIM - DomainKeys Identified Mail

DKIM is an authentication method, which uses encryption with public/ private keys, to validate whether the emails are generated from the authorised servers, recognized and configured by the administrators of the sending domains.

Why configure DKIM?

Spammers often send out emails that claim to be from authentic email senders. These emails are mostly sent with an intent to make the recipients view the email, or sometimes to collect sensitive information (passwords, email addresses etc.) from the recipients under the pretext of being a legitimate sender. Two methods that are commonly used by spammers include email spoofing and backscattering.

Email Spoofing:

Email spoofing is a cheating method used by spammers to make emails appear to be sent from a legitimate domain/ email address, that does not belong to them. This is done by forging the email headers, to make it seem legit so that the recipients trust and open the emails.

Spammers follow this approach as it makes more people view the email since the sender appears to be authentic. But, sometimes, it may pose serious consequences if they try to retrieve sensitive information from the user. Spoofed emails can be detected and avoided by configuring SPF and DKIM. If DKIM is configured, the domain name identity associated with each message is validated.

If this DKIM validation fails, such emails are quarantined or rejected based on the conditions set by you when DKIM validation fails.

Email Backscattering:

Spammers spoof a domain name and send emails using the tampered email address. If the recipient domain rejects the email, it will send bounce messages to the domain that was spoofed.

Consider a case where a spammer has spoofed your email address and sent spam emails to another domain. When these spam emails are sent to invalid email addresses, the recipient domain sends a bounce message to the spoofed domain. This bounce message, instead of being sent to the spammer will be sent to the spoofed domain from which the user is claiming to send the email. The spoofed domain will also be blacklisted by the recipient domain. If DKIM is configured, the authenticity of your domain can be validated and your domain blacklisting can be avoided. In case you’re on the receiving end of these spam emails, DKIM can help detect the authenticity of the emails, and those emails that are not genuine will not be delivered to your mailbox.

Email spoofing and backscattering, two methods that are commonly used by spammers, can be prevented to a certain extent by configuring SPF and DKIM for your domain.