>>> # Deny e-mail with no sender address.
>>> deny condition = ${if eq {${strlen:$sender_address}} {0}}
>>> message = E-mail with '$sender_address' as sender address!
>>> logwrite = E-mail with '$sender_address' as sender address - 'mime' acl deny!
>> Is there a good reason why that stanza exists in your configuration? As
>> you've discovered, it'll outright reject well-formed bounces / NDRs.
> You definitely don't want to do that before DATA, since it'll mean that you can't deliver to sites that perform sender verification callouts.
>> (Also, the use of $sender_address in the messages is a tad redundant
>> given you've confirmed it to be zero-length :) )
The above check for no sender address has now been removed.
As I said in my original post, I am a part-time Exim admin who inherited the system and I tinker with it occasionally.
I admit my understanding of Exim and SMTP is limited so thank you for your help.
Thanks again
Paul McIlfatrick
