If there is a syntax problem with the filter, then look for the following message in the tcp_local_slave.log-* file:
Error parsing filter expression:...
If the filter is good, then filter information will be at the end of the output.
If the filter is bad, then the following error will be at the end of the output:Address list error -- 4.7.1 Filter syntax error: desdaemona@sesta.com
Also, if the filter is bad, then the SMTP RCPT TO command will return a temporary error response code:
RCPT TO: user@domain 452 4.7.1 Filter syntax error |