best practice removing/rejecting message having files with specific extensions.

[none]

I like to reject messages based on their attachments file extensions. I
assume this can be best done with a milter? Any recommandations?

[Marco Moock]

Post by none
I like to reject messages based on their attachments file extensions.
I assume this can be best done with a milter? Any recommandations?

MIMEDefang can handle that.
This describes the MIMEDefang stuff.
https://www.axigen.com/knowledgebase/How-to-Configure-and-Integrate-Axigen-and-MIMEDefang-to-Block-Attachments-by-File-Extension_340.html

[none]

Post by Marco Moock

Post by none
I like to reject messages based on their attachments file extensions.
I assume this can be best done with a milter? Any recommandations?

MIMEDefang can handle that.
This describes the MIMEDefang stuff.
https://www.axigen.com/knowledgebase/How-to-Configure-and-Integrate-Axigen-and-MIMEDefang-to-Block-Attachments-by-File-Extension_340.html

I was just about to give this a try and on el9 this has 116 package
dependencies ~260MB. Is there not some smaller solution for hanling some
file extensions? :)

[d***@dl8fbh.ampr.org]

Post by none

Post by Marco Moock
MIMEDefang can handle that.
This describes the MIMEDefang stuff.
https://www.axigen.com/knowledgebase/How-to-Configure-and-Integrate-Axigen-and-MIMEDefang-to-Block-Attachments-by-File-Extension_340.html

I was just about to give this a try and on el9 this has 116 package
dependencies ~260MB. Is there not some smaller solution for hanling some
file extensions? :)

procmail

Mike

[Grant Taylor]

Post by d***@dl8fbh.ampr.org
procmail

Removing the files w/ specific extensions with the procmail LDA after
accepting the message is different than rejecting them during SMTP time.

I suspect that it's possible to tune SpamAssassin and / or ClamAV to
object to the file extensions and have the milter reject the message
during the SMTP transaction. Though that's predicated on configuration
using them.

There's probably also a way to create a custom rule that will cause
Sendmail to reject it directly. There are probably some guides on
fighting spam from the mid-to-late '90s that may have information on how
to do that.