| /service=service | mailbox access service, default is "imap" |
| /user=user | remote user name for login on the server |
| /authuser=user | remote authentication user; if specified this is the user name whose password is used (e.g. administrator) |
| /anonymous | remote access as anonymous user |
| /debug | record protocol telemetry in application's debug log |
| /secure | do not transmit a plaintext password over the network |
| /imap, /imap2, /imap2bis, /imap4, /imap4rev1 | equivalent to /service=imap |
| /pop3 | equivalent to /service=pop3 |
| /nntp | equivalent to /service=nntp |
| /norsh | do not use rsh or ssh to establish a preauthenticated IMAP session |
| /ssl | use the Secure Socket Layer to encrypt the session |
| /validate-cert | validate certificates from TLS/SSL server (this is the default behavior) |
| /novalidate-cert | do not validate certificates from TLS/SSL server, needed if server uses self-signed certificates |
| /tls | force use of start-TLS to encrypt the session, and reject connection to servers that do not support it |
| /notls | do not do start-TLS to encrypt the session, even with servers that support it |
| /readonly | request read-only mailbox open (IMAP only; ignored on NNTP, and an error with SMTP and POP3) |