POP3 SASL SASL AUTH PLAIN RFC1734 RFC4616 RFC5034 # Server-side AUTH PLAIN REPLY AUTH + REPLY %b64[shared-mailbox%00user%00secret]b64% +OK Login successful From: me@somewhere To: fake@nowhere body -- yours sincerely # Client-side pop3 POP3 plain authentication with alternative authorization identity pop3://%HOSTIP:%POP3PORT/%TESTNUMBER -u user:secret --sasl-authzid shared-mailbox # Verify data after the test has been "shot" CAPA AUTH PLAIN %b64[shared-mailbox%00user%00secret]b64% RETR %TESTNUMBER QUIT