[CentOS] Creating a Roaming imap account

Tue Feb 5 17:20:18 UTC 2008
Bill Campbell <centos at celestial.com>

On Tue, Feb 05, 2008, Anne Wilson wrote:
>This (CentOS5.1) box is my new imap server.  Using 
>system-config-security-level I opened port 143 tcp, and mail is readable 
>throughout the LAN.  I want a Roaming account on my laptop so that I can read 
>mail while away from home.  I have set up the account in kmail, and I know 
>that that part is correct, as it worked on my old, less-secured, imap server.  
>However, I haven't been able so far to make a connection.
>
>Do I need 143 udp open?  What else must I do to allow me to connect over WAN?

You should have port 993 open which provides security via SSL.
One can use TLS to initiate connections via port 143, but this
may result in unencrypted logins which result in your username
and password being sent in clear text across the Internet.

You will also have to make provisions to allow mail relaying from
the roaming IP for the duration of the authenticated connection
(assuming that your mail server is not an open relay which will
get it black listed pretty quickly).  There are various ways to
handle this.  We have used WHOSON for years which doesn't require
any action on the part of the IMAP client.  One can also use SMTP
AUTH, POP/IMAP before SMTP, or other methods.

It would probably be easier to set up OpenVPN so you can tunnel
from the remote systems into your private network, then connect
via the private IP address for IMAP and SMTP sending.  Once one
has generated the proper keys for the OpenVPN connections, it is
easy to make the connections (and easy to revoke them as well).
There are OpenVPN clients for the Microsoft virus, Windows, OS X,
and every version of Unix I've used.

Bill
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