Re: verify recipient - temp error instead of perm error

Ahoj,

Dňa Wed, 13 Aug 2025 08:46:50 +0200 Frank Richter via Exim-users
<[email protected]> napísal:

> Now, (how) can I change this message  '451 Temporary local problem -
> please try later'?
> This causes questions to me: Please fix your local problem :-)

It was nice exercise for me :-P

It can be done by nested ACL, first define named ACL somewhere:

    # distinguish temporary error in recipient verify, sets acl_m_rvrfy
    rcpt_verify:

      # set temporary error result
      require       set acl_m_rvrfy = defer

      # on success verify
      accept        verify          = recipient
                    set acl_m_rvrfy = accept

      # on failed verify
      deny          set acl_m_rvrfy = deny

It is based on fact, how verify and nested ACLs works:

+ if success, the nested ACL sets value to variable to accept
  (actually unused) and returns accept
+ if failed, the nested ACL continues to deny where is unconditionally
  sets variable value to deny
+ if verify defers, the nested ACL returns that and initial value of
  variable remains

Then use it in RCPT ACL (add more conditions as appropriate) , where
nested ACL is called to set variable, then i act on variable value as
needed:

    require         set acl_m_rvrfy =
    warn            acl             = rcpt_verify

    deny            condition       = ${if eq{$acl_m_rvrfy}{deny}}
                    message         = Unroutable recipient domain

    defer           condition       = ${if eq{$acl_m_rvrfy}{defer}}
                    message         = Temporary unroutable recipient domain

The only problem is, that temporary verify errors can be caused not
only by DNS, but IMO this message is better as default one...

regards

-- 
Slavko
https://www.slavino.sk

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