On 6/17/22 22:18, Austin Witmer wrote:

For some reason I am now getting five duplicate emails placed in my sent folder

Saw your log on the postfix list.

Indeed the message is received again from amavisd via SMTP.

The configuration you have simply says that every time a message comes in from user@mydomain.com, a copy should be sent to user+sent@mydomain.com. Since it goes out to amavisd and in again, the rule is reapplied. You clearly have a counter somewhere which is stopping this from going on infinitely.

You want to apply this rule only once, perhaps on the way back in from amavisd. This can probably be accomplished by applying the sender_bcc_maps to a specific listener in master.cf, for the general idea see examples here:

https://www.postfix.org/ADDRESS_REWRITING_README.html