Returned notification: 550 Cannot process address

  • 7025153
  • 14-Jun-2021
  • 14-Jun-2021


GWAVA (Secure Messaging Gateway) 7


External email is not being delivered through Secure Messaging Gateway (SMG).

Sender is receiving a failed delivery notification that states: 550 Cannot process address

In the SMG SMTP log, seeing entries like:

Authenticating to server
Authentication failed to server 501 Authentication failed
Could not authenticate connection with host with user <user@domainname> as required
Retrying non-TLS connection to SMTP host at


In the SMG Admin Console | Organizational/Policy Management, Domain Management, SMTP HOSTS, Target Type, SMTP Server, the Username has accidentally been populated with a user@domainname address.

Remove this address and save changes. Email will now flow through SMG correctly.