SMTP error from remote mail server after RCPT TO:<firstname.lastname@example.org>: host mx.server.com [xxx.xxx.xxx.xxx]: 550-Verification failed for <email@example.com> 550-The mail server could not deliver mail to firstname.lastname@example.org. The account ordomain may not exist, they may be blacklisted, or missing the proper dns entries. 550 Sender verify failed
If you are a ISPConfig web host, you would recognize this as one of the common errors reported by your customers.
Sender verify failed can be caused by issues ranging from improper file permissions to RFC non-compliance. Engineers at Bobcares help desk support services collect detailed information regarding the error through log analysis and engaging the customer. The following are the few of the common causes for this error. Continue reading