vvrpgsporcupineorg chantal rosmuller hi try send mail existing user get following error 451 435 server configuration error httpwwwposfixorgdebug_readmehtmllogging look obvious signs trouble postfix logs failed successful deliveries logfile file usually called varlogmaillog varlogmail exact pathname defined etcsyslogconf file postfix receive deliver mail first order business look errors prevent postfix working properly egrep warningerrorfatalpanic somelogfile note important message near beginning output error messages come later less useful nature problem indicated follows panic indicates problem software programmer fix postfix proceed fixed fatal result missing files incorrect permissions incorrect configuration file settings fix postfix proceed fixed error reports error condition safety reasons postfix process terminate 13 happen warning indicates nonfatal error problems may able fix broken dns server elsewhere network may also indicate local configuration errors could become problem later thu 07 aug 2008 184607 0500 cant get check_recipient_access working