i don't know when this change happened, but i see bugs.devuan.org using
" X-Mailer: MIME-tools 5.509 (Entity 5.509) "
which is clarified as spam in some systems, because of "Entity".
a very common rule for mass mailers in email header_checks.. our own rule :
Internet Tool|DejaVu|DiffondiCool|E-Mail Delivery Agent|Emailer
Mail|Direct Email |Andrew's SuperCool Blastoise|MailerGear|Advanced Mass
Sender|SpireMail|UltimDBMail|Mabry)\b/ REJECT No mass mailers allowed.
You are probably sending spam
came accross this, when i saw that an old bug was closed, and according
to bugs.d.o i was notified, but never got an email..
so, looked into mail.log and found out why.
it wasn't like that before, see following examples :
newest blocked message with entity x-mailer :
older message received normally, without x-mailer header :
Subject: Re: bugs.devuan.org using mass mailer Entity, classified as spam..
Date: Fri, 31 Jan 2020 17:46:01 +0000
Control: tags -1 wishlist
I suppose this happened when we migrated the bugs.d.o server and upgraded
to debbugs 2.6.0.
I will look to see if it is possible to hide the X-Mailer header.
Presumably you could whitelist bugs.d.o?