Lookup for "235 2.7.12"
This status code indicates a successful delivery or other operation. Any details are simply notes.
Basic Status Code Details (235)
Authentication succeeded
Enhanced Status Code Details (2.7.12)
Password transition required
The user needs to transition to the selected authentication mechanism. This is typically done by authenticating once using the [PLAIN] authentication mechanism. The selected mechanism SHOULD then work for authentications in subsequent sessions.