Spam bypassing domain name mailbox addresses


#1

Can anyone tell me how to stop the delivery to my mailboxes of mail addressed to myuser/mailboxname@baracus.dreamhost.com, @murdock.dreamhost.com etc.?

I want no such exposure to spam.

Thanks.


#2

Well not fully back from vacation, but my flight is delayed (it’s raining here) and I’m bored.

There’s no easy way, but I’ll bet that if you look closely, the mail in question is probably actually delivered to addresses at your domain. It’s pretty rare to see mail that’s actually being sent to username@[mail machine] unless you’re posting full headers of emails sent to you somewhere public. Technically, it’s possible to block mail to these addresses, but I won’t usually do it unless you’re actually seeing spam to these addresses.

If you have headers showing otherwise, feel free to pass them along to me via support (I think there’s been another thread about this recently).


#3

There’s no “mail in question” yet.

Thanks.


#4

[quote]It’s pretty rare to see mail that’s actually being sent to
username@[mail machine] unless you’re posting full headers

[/quote]

Hmm… I just discovered /DH/ is posting the internal address…

…in the DFR:

Final-Recipient: rfc822; mXXXXXXX@murdock.dreamhost.com
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Postfix; maildir delivery failed: error writing message:
Disk quota exceeded


#5

Yeah - I wouldn’t worry about it unless it becomes a problem. If you’re posting spam to any public forums (news.admin.net-abuse.sightings, for example), you’d want to make sure to remove any delivered-to headers and other headers which show the final destination mailbox (username@machine.dreamhost.com). Unless those addresses get posted somewhere, it’s unlikely that you’ll get spam there, unless maybe it’s a really common name.

What we can do if it becomes a big problem is to define an access map entry to prevent external mail from getting sent to that address… however I don’t like to do that unless it’s absolutely necessary.


#6

Its good to hear you have a plan, given the machine hostnames are bound to reach a spammer’s domain list eventually :frowning:

And I’ll resist the temptation to use the machine address for any legit mail! :wink:

Thanks.