On Tue, May 25, 2010 at 12:37, Wietse Venema <wie...@porcupine.org> wrote: > Phil Howard: >> On Tue, May 25, 2010 at 10:36, Wietse Venema <wie...@porcupine.org> wrote: >> >> > Postfix supports wildcards via regexp/pcre tables. >> > >> > ?1) You can use them for all the tables that define Postfix address >> > ? ?classes: mydestination + aliases, virtual_alias_domains + >> > ? ?virtual_alias_maps, virtual_mailbox_domains + virtual_mailbox_maps, >> > ? ?relay_domains + relay_recipient_maps. >> > >> > ? ?Simply replacing one domain name by another does not produce the >> > ? ?expected result. >> >> That's what I'm afraid of ... particularly if it can result in >> backscatter or open relay. I need to get the test of the valid user >> done at RCPT time, obviously. But the addressed domain could be >> foobar.example.com or xyzzy.example.com or anything else in front of >> the domain, without me knowing what these could be in advance. So I >> can't just have a table of all possible valid u...@hostpart.domain. I >> can have all valid u...@domain even though RCPT can name >> u...@hostpart.domain. > > Postfix supports wildcards via regexp/pcre tables: > /^u...@.*\.example\.com$/ will match the user in any subdomain of > example.com.
But this is still going to be a big table with individual entries for all users? > >> > ?2) Postfix 2.7 supports SMTP command rewriting (smtpd_command_filter) >> > ? ?However this would produce an incorrect error message: >> > >> > ? ?RCPT TO:<u...@foo.example.com> >> > ? ? ? ?smtpd_command_filter strips this to ``RCPT TO:<u...@example.com>'' >> > ? ? ? ?The Postfix SMTP server then responds with: >> > ? ?550 5.1.1 <u...@example.com> User unknown > > In this example, the user really does not exist. Postfix does not > produce an error message when u...@example.com exists. But if I just use a pattern for "user", it's going to look valid no matter what username is mailed to, and my server becomes a backscatter source. So I need to have the user in there, it seems. Same problem as my other need to translate a domain.
