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Accepted
Joachim Breitner
Asked: 2015-05-11 01:47:44 +0800 CST

exim: redirect all but a number of local parts

  • 772

On my server, I implement redirects using this router

virtual_aliases:
  driver = redirect
  allow_defer
  allow_fail
  data = ${lookup{$local_part@$domain}wildlsearch*@{/etc/vhosts/forwards}}
  domains = /etc/vhosts/maildomains
  qualify_preserve_domain
  retry_use_local_part

and entries in /etc/vhosts/forwards like

[email protected]: [email protected]
^.*@example2.com: [email protected]

This works fine and as intended. Now my customer asks me to change the second line to “forward all, with the exception of [email protected] and [email protected]”, as these attract too much spam.

Is there a nice way to implement this logic inside the /etc/vhosts/forwards, or would I have to add another blacklisting router?

redirect

3 Answers

  1. Just add a condition to the router:

    virtual_aliases:
  driver = redirect
  allow_defer
  allow_fail
  condition = ${lookup{$local_part@$domain}wildlsearch*@{/etc/vhosts/stoplist}{no}{yes}}
  data = ${lookup{$local_part@$domain}wildlsearch*@{/etc/vhosts/forwards}}
  domains = /etc/vhosts/maildomains
  qualify_preserve_domain
  retry_use_local_part

    If address is listed in the /etc/vhosts/stoplist no redirection will be performed.

    • 2
  2. Best Answer

    You can selectively bounce email in the alias file /etc/vhosts/forwards, or just have it disappear. See the documentation on special items in lists, aka alias files (bullet items 4 & 5 as of Oct-14-2015).

    # efficiently and silently discard this email after accepting it 
[email protected]: :blackhole:

# bounce this email. message is optional. 
[email protected]: :fail: User no longer available

# forward the rest 
[email protected]: [email protected] 
^.*@example2.com: [email protected]
    • 1

  3. It seems that this is possible within the forwards file, by specifying no addresses to forward to:

    [email protected]: [email protected]
[email protected]:
[email protected]:
^.*@example2.com: [email protected]

    This seems to be documented behavior (and not just a lucky implementation detail):

    If the lookup fails, the expanded string in this example is empty. When the expansion of data results in an empty string, the router declines. A forced expansion failure also causes the router to decline; other expansion failures cause delivery to be deferred. Source

    • 0