Cisco ESA Email block notification

[egsuptac911]

I have several mails blocked due to senderbase reputation from legitimate sender, whitelisting will solve the issue but i need the sender to get notified if that possible.

And if sender message blocked due to mail policy ,sender and recipient get notified in order to communicate with ESA admin.

[Libin Varghese]

Emails blocked by poor senderbase scores are rejected with code 554 and message email rejected due to sending MTA poor reputation.

As per RFC the notification or NDR has to be generated by the server in possession of the email. During senderbase check at HAT, ESA has just received a connection from the sending server and does not have information about the sender or recipient email address to generate a notification. Ideally based on the 554 code returned by the ESA, the sending server should notify the sender email address that their email attempt was rejected.

If you would like ESA to generate the notification instead, you would need accept all connections coming to it under HAT and then use content/message filters to drop the email and generate notifications. However, this could increase the load on the appliance many fold since a lot of emails from known spam sources would need to be processed instead of being dropped initially at the connection level.

Regards

Libin