Option to disable IMAP Auth

[sniffingsugar]

Hi,

maybe it is good to add an Option to disable the IMAP Auth, in some cases it can be helpful.

Example:
Gmail BCC -> Mailcow BCC -> Mailpiler
In this case we have an alias that the fetch from the mailcow api dont support and also you cant add this alias to mailcow (or add gmail.com to accepted domain tf this is weird)

If you try to add this account manual from webui you cant add this because the user has already logged in via IMAP.

Best regards
Phil