Forcing Outlook to communicate on specific ports

[DavidS]

We are using Outlook 2003 to connect to an IMAP server and everything seems
to be working fine. Due to security standards, we need to lock down any
unused ports with firewall rules and specifically add rules for applications
and services.

Using netstat I've noticed Outlook connecting to the IMAP server using
random ports (so far in the 1000-2200 range). Is there a specific range of
ports Outlook uses or can Outlook be forced to use specific ports?

TiA

 

[Brian Tillman [MVP - Outlook]]

We are using Outlook 2003 to connect to an IMAP server and everything
seems
to be working fine. Due to security standards, we need to lock down any
unused ports with firewall rules and specifically add rules for
applications
and services.

Using netstat I've noticed Outlook connecting to the IMAP server using
random ports (so far in the 1000-2200 range). Is there a specific range of
ports Outlook uses or can Outlook be forced to use specific ports?

For us, Outlook's IMAP uses the port we specify in the account
configuration, usually 143. We have no ports between 1000 and 3000
listening on the server side.

 

[DavidS]

Yes, the server listens on 143 as configured. What we're trying to control
is which port the client initiates communication on. When we ran the netstat
command on the client, that's where we saw the random port connections to the
mail server using IMAP or SMTP. Ideally, we'd like to make this a fixed port.

 

[Brian Tillman [MVP - Outlook]]

Yes, the server listens on 143 as configured. What we're trying to
control
is which port the client initiates communication on. When we ran the
netstat
command on the client, that's where we saw the random port connections to
the
mail server using IMAP or SMTP. Ideally, we'd like to make this a fixed
port.

As I said, from the client to the server will be a fixed port. We don't
have any of those other ports open on the server and yet IMAP works.