0

My wired internet connection at work blocks the IMAP, POP and SMTP ports (the mail server is Exchange) which prevents me from using an email program like ThunderBird.

With the internet cable plugged in I can only use ThunderBird to read my work e-mail -- gmail is blocked by the firewall.

The guest wireless connection at work has the mail ports open. I thought this answer to link the gmail server address specifically to my wireless connection had solved my problem: with the network cable disconnected, I could read and write gmail.

But there are still two problems:

  1. With only wireless, authentication fails for my work Exchange server -- so I need my firewalled work connection for that
  2. As soon as I connect the network cable, the Exchange server works but then gmail fails because that also goes via the wired -and firewalled- connection.

I thought the answer above would solve this by routing traffic for gmail via the wireless gateway and Exchange traffic via the default (wired) gateway. But that's not the case when I plug in the cable.

My guess is that ThunderBird overrides this setting? Is it possible to assign a connection to an e-mail account or server address in another way?

Community
  • 1
alle_meije
  • 327

1 Answers1

1

Playing with routing tables, as in the other answer, would seem to be the right solution to this, I think. However, just doing a 'ping' to a google imap server and then rerouting only that one through the wireless may be a little bit optimistic; I sincerely doubt that google has only one IMAP server.

Instead, I would suggest you modify your routing table in the following way:

  • Make sure there is no default route to the wired network, but remember what the IP address of the default router on that wired network is.
  • Add routes for all RFC1918 networks (10.0.0.0/8, 172.16/12, 192.168/16) to your routing table, with the IP address of the default router on that wired network. If the IP address on your wireless network uses an RFC1918 network too, however, make an exception for that.
  • Keep the default route on the wireless network.

This way, everything for "the Internet" will go over the wireless interface, and everything for your local LAN (including the local mail server) will go over the wired interface.

Wouter Verhelst
  • 396