Use VPN with Thunderbird and rest of traffic through ISP ?

Title says it all, can it be done?

I have a VPN and love using Thunderbird. Some email providers strip the email client and sender's IP from the header when using a client, others don't. The email client user agent can actually be edited by yourself in the Thunderbird settings, however stripping the sender's IP from the email header only works when using VPN to have the VPN's IP show up on outgoing messages.

Does anyone know how I could possibly split up the internet connection to one part purely using the VPN for Thunderbird only and the rest of the connection goes through the ISP for all other services?

If not splitting up the connection with a software or tool, could some hardware be used to achieve this? A splitter or switch or hub of some kind?

Note this is for one computer, having two or more computers this is easy to do of course.

 

VM is all I can think of. TBird and OpenVPN on the VM, Host using bare internet connection.

PD

 

I researched possible options too and came up with the concept of split tunnelling.

Could this eventually lead me to the solution as opposed to setting up a VM?

In split tunnelling exactly the use case I am wanting to achieve would be the case, access the company network, in my case the Thunderbird email servers, over the VPN and do everything else over the ISP.

My VPN provider supports OpenVPN with a configuration file, this guide from Stevens could be used to set up split tunnelling and then I would only need to tell Thunderbird in the network settings to use the VPN connection as opposed to my normal internet connection.

Would that work out? I am pretty hopeful in all parts except the last one, not quite sure yet how to tell Thunderbird to only use the VPN settings. Am I barking up the wrong tree here or does my train of thought make any sense?

 

I've forgotten most of what I ever knew about Windows

But I think that you can set firewall rules to specify which network connection each app will use.

However, I'd just do as PaulyDefran suggested. Run a VM with a VPN client, and whatever (Thunderbird etc) you want using the VPN.

 

Will running a VM purely for the task of sending and receiving email not be overkill on the system?

Is there a lightweight VM that can run on an per application basis?

Can I quickly switch between the VM and the normal OS so that my workflow is not interrupted by rebooting etc. When on the normal OS how do I get notified about incoming email on Thunderbird on the VM?

What VM, possibly open source or free, should I be looking at?

Will the VM be getting it's own local IP on the network, similar to having another PC connected to the network?

How about setting up Proxifier to use the VPN purely for Thunderbird? Would that work?

 

VirtualBox with a light Linux distro runs on just about any modern hardware.

I don't know. I vaguely recall that running virtualized apps is doable in VMware, but

The VM is just another window on your desktop, so switching is trivial.

I suggest Ubuntu, Xubuntu or Crunchbang (very light and pretty).

It can, with bridging to host network adapter. Or it can get a private IP from VirtualBox DHCP server (NAT option in VM setup).