On Mon, May 05, 2003 at 10:36:37AM -0400, Courier User wrote:
I forgot to mention that many of the spams are being sent to
postmaster at my host, which is an existing mailbox. This large
group of spams are being rejected by courier because their "from"
address is illegal: <#@[]>
That's not an incoming message - that's a double-bounce, a message generated
internally by your mailserver.
1. Incoming message:
MAIL FROM: <bada...@baddomain.com>
RCPT TO: <some...@yourdomain.com>
2. Fails your filters
3. Bounce is generated:
MAIL FROM: <>
RCPT TO: <bada...@baddomain.com>
4. Bounce fails to be delivered because of invalid address
5. Double-bounce is generated:
MAIL FROM: <#@[]>
RCPT TO: <post...@yourdomain.com> <<<<<<<<
So the spam wasn't necessarily to 'postmaster', it could have been to any
user at your domain.
In my experience, in the absence of configuration errors, double-bounces are
all attempts to return spam with invalid envelope-sender, so I just discard
these errors silently.
However, whenever you are making changes to your MTA configs, it's advisable
to keep and examine double-bounces for a while: they may point out a
configuration error that you had overlooked.
Regards,
Brian.
12 messages in net.sourceforge.lists.courier-usersRe: [courier-users] Re: Controlling w...
