Sending Email via SMTP relay

Sometimes Emails cannot be simply sent from the platform's MTA — your company can have regulations about security and data loss prevention, that will add a relay (proxy or DLP) to your sending process.

note

To collect information about delivery and customer activity, your relay must support DSN.

Also check PTR record for AKMTA and whether it is accessible from the SMTP relay server.

In Altcraft Marketing Administrative panel create a sender and enable "Send via SMTP relay".

note

If you do not use DKIM, add it for your SMTP relay.

Postfix

By default Postfix is configured to notify on message delivery only in case the receiving server does not support DSN. Otherwise it will resend the report to the receiving server. The solution here is to disable DSN for all servers.

Settings

In Postfix configuration file (/etc/postfix/main.cf) add this parameter:

smtp_discard_ehlo_keyword_address_maps = cidr:/etc/postfix/esmtp_access

Create file /etc/postfix/esmtp_access with a list of receiving servers supporting DSN:

10.10.0.0/16  silent-discard
0.0.0.0/0     dsn
::/0          dsn

Documentation:

• http://www.postfix.org/DSN_README.html
• http://www.postfix.org/postconf.5.html

note

Be careful not to mistake smtp_discard_ehlo_keyword_address_maps for smtpd_discard_ehlo_keyword_address_maps.