imap-open

imap-open is a compiled Lisp function in `imap.el'.

(imap-open SERVER &optional PORT STREAM AUTH BUFFER)

Open an IMAP connection to host SERVER at PORT returning a buffer.
If PORT is unspecified, a default value is used (143 except
for SSL which use 993).
STREAM indicates the stream to use, see `imap-streams' for available
streams. If nil, it choices the best stream the server is capable of.
AUTH indicates authenticator to use, see `imap-authenticators' for
available authenticators. If nil, it choices the best stream the
server is capable of.
BUFFER can be a buffer or a name of a buffer, which is created if
necessary. If nil, the buffer name is generated.