postfix header check

sirjosi · 12-02-2003, 12:58 PM

environment:
redhat 9
postfix
pop before smtp

Ive set up header check to bounce back anything going to a certain person, say

/^to: aaa@aaa.com$/ REJECT (aaa.com being a valid virtual domain)

I then mapped this email to my user name to see if it is still receiving any emails. When I try to send from yahoo to aaa.aaa.com, it gets rejected (yay!)

Yet Im still getting spams to this address. How are they getting in? To make matters worse, I'm also getting aaa@bbb.com where bbb.com isnt even on my domains list

thanks for any help

chort · 12-02-2003, 01:40 PM

The RFC821 and RFC822 headers don't have to agree. What you're filtering on is the RFC822 (message header) but in order to get the message to you, only the message envelope needs to point to your address.

I think Postfix has support for user maps. You could always point that user to /dev/null.

sirjosi · 12-02-2003, 06:07 PM

thanks however, this rule should apply not just for existing users right?

Im actually using this header check to make my catchall account easier to browse through for valid emails that may have been sent to the wrong email address say aaa1@aaa.com. Our clients just love us for catching these types of good emails.

Therefore I cant just point a user to a null destination

chort · 12-02-2003, 06:11 PM

Ahh, so you're directing the "left overs" that don't go to an actual user into a catchall account? Right, you do not want to /dev/null your catchall. However, you should be able to setup a usermap and "create" the invalid user, and direct just that user to /dev/null. *DISCLAIMER I haven't done this with Postfix so it's all a theory, but it's a theory based on about 7 years of e-mail administration.

sirjosi · 12-02-2003, 06:17 PM

but that would mean having to make a bunch of non real users just to throw away the bad mail, this isnt so bad but we may be talking about tens to hundreds of bogus users

It would be really nice to have the to: caught by the above syntax or any other means

chort · 12-02-2003, 07:07 PM

You can do that only if the filter hooks into the MTA to read the RCPT TO: rather than just scanning the To: on the message header. The SEIVE filter in Qmail will let you do the former. There must be something similar in Postfix, but like I said, I'm not familiar with it.

sirjosi · 12-02-2003, 07:09 PM

this sounds like a good lead.

thank you so much