Rob Wilson writes:
The first 3 remote users will be accepted but the system will reject
the last because the MAIL FROM is being sent empty.
This has only been an issue recently with this specific server.
Which should tell you something.
The spam software is absolutely causing the rejects. But it's doing so
because of the empty MAIL FROM.
Is courier correct in sending the empty MAIL FROM or am I missing a
setting? Or is the spam software misbehaving?
The so-called 'spam software' is broken.
This is a judgement call.
Aliases should really be used for internal mailboxes only. They work
perfectly well for external addresse, but if you really want to run a
mailing list, use mailing list software, instead of aliases.
When mail gets forwarded through an alias, and gets bounced, if the original
sender's software uses automated bounce processing, it will obviously have
no knowledge whatsoever about the aliased address, that it knows nothing
about, and will not be able to identify and remove the undeliverable mail
address. That's considered to be rather rude behavior.
For this reason, mail forwarded through aliases have DSN=NONE set, to
suppress any bounces. If the remote mail server is an ancient dinosaur that
does not implement the DSN ESMTP extension, an empty return address is used
as a fallback measure.
2 messages in net.sourceforge.lists.courier-usersRe: [courier-users] Empty MAIL FROM w...
