Issue with port forwarding https/webmail

[kkm]

Hi!

I'm new to this forum, so I hope this is the right place for the post.

We have an email server running Mac Lion 10.7 that has roundcube webmail set up on it using a self-signed SSL certificate.  Roundcube is running the default MAC settings.  Internally, webmail connections work using https on port 443.  No other ports are needed internally for webmail to work.  Externally (outside of the firewall), web browsers will not connect to the webmail unless port 143 (unencrypted IMAP) is also port forwarded to the webmail server.  I also have to change the email server from "Require SSL" for IMAP to "Use SSL" for IMAP.  If I don't do these two things, external webmail won't work.  This has been replicated on multiple accounts, computers, locations, and browsers.

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Here is what I get in the webmail/errors file:

"IMAP Error:  Login failed for [email protected] from xxx.xxx.xxx.xxx. (Client IP address)  Could not connect to xxx.xxx.xxx.xxx:143: (firewall interface ip address)  Operation timed out in /usr/share/webmail/program/include/rcube_imap.php online 192 (POST /webmail/?_task=login&_action=login)"

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Here is the rule that we have for webmail:

Dest. Addr       Dest. ports     Nat IP      Nat Ports
*                   25000            server      443


We are using port 25000 as the destination port since we have other https connections on the standard ports already going to other servers.  Also, we are connecting directly to the firewall external interface with https://firewall-ip-address:25000/webmail to access the server.

1.  Why is roundcube saying that the external interface of the firewall is trying to log in with standard imap when using HTTPS?

2.  Is there another firewall/roundcube setting that we should be using to allow port forwarding for SSL connections?  I will be happy to supply anything else needed for troubleshooting.  I believe the version is 0.5.3, but I also will need assistance to check the version.  Thanks!