post...@fongaboo.com: > Jan 31 20:06:15 h6lix postfix/smtp[6552]: 7128C4089C: > to=<outsideaddr...@swling.net>, relay=50.75.172.140[50.75.172.140]:25, > delay=2.5, delays=0.64/0.01/1.6/0.23, dsn=4.3.0, status=deferred > (host 50.75.172.140[50.75.172.140] said: 451 4.3.0 Error: queue > file write error (in reply to end of DATA command))
You need to look in the logs on 50.75.172.140. The Postfix SMTP server returns a generic "write error" without revealing details in its responses to an SMTP client. Wietse