Maurizio Caloro: > >Jun 18 14:30:24 nmail postfix/cleanup[32365]: 23A3440631: milter-reject: > END-OF-MESSAGE from deferred1.pod17.euw1.zdsys.com[188.172.137.31]: 4.7.1 > Service unavailable
The 4.7.1 means "try again later". The remote SMTP client decides
when it retries.
If you don't want the client to retry, the reply should be 5.7.1.
Wietse
