I noticed starting today the Sender: header is no longer included on the mailing list. I used to use the Sender: header in sieve rules for sorting. Now the list emails only come From: rando email addresses. On the postfix mailing list it replaces the From: header with the list address instead of keeping the original email author.

Is this the future intended behavior? Or can we get a Sender: or From: header to contain the list address for sorting?

Um okay, THIS email coming through the list did change the From: header to the list address. I guess problem has been resolved since the last few list emails received.

Citeren dovecot--- via dovecot <dovecot@dovecot.org>:

I noticed starting today the Sender: header is no longer included on
the mailing list. I used to use the Sender: header in sieve rules for sorting. Now the list emails only come From: rando email addresses. On the postfix mailing list it replaces the From: header with the
list address instead of keeping the original email author.

Is this the future intended behavior? Or can we get a Sender: or
From: header to contain the list address for sorting?

Use the List-Id header instead:

 List-Id: Dovecot Mailing List <dovecot.dovecot.org>