Hello. I am getting [somebody]@tiscali.co.uk; Failed; 5.1.1 (bad destination mailbox address)
Remote MTA mx.tiscali.co.uk: SMTP diagnostic: 550 5.1.1 5VxYcKmkFowYI Recipient Undeliverable (TT512).
Does this mean the address is incorrect or could there be another reason for the failure?
Many thanks.
David