Old RFC-821 style addresses like:
Makes James (SMTPServer, but the actual bug is in the mailet api's MailAddress):
ERROR smtpserver: Error parsing sender address: @YYY.XXX.DK:zzz@XXX.dk: No
local-part (user account) found at position 1
Which is logical as MailAddress is not designed to handle source routes.
But according to RFC-2821 appendix F.2:
"SMTP servers MUST continue to accept source route syntax as specified in the main body of this document and in RFC 1123. They MAY, if necessary, ignore the routes and utilize only the target domain in the address. If they do utilize the source route, the message MUST be sent to the first domain shown in the address. In particular, a server MUST NOT guess at shortcuts within the source route."
So to be compliant James actually MUST accept this syntax
Proposed fix is to ignore the source routes and use the target domain as suggested in the quote above. This is also the way the Postfix mailserver handles this.