Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

How do I access POP/IMAP/SMTP through a proxy? (The proxy settings in Thunderbird do not work.)

share|improve this question
Which POP/IMAP/SMTP, which proxy? What are your current settings in Thunderbird? In which network are you? What operating system do you have? You might want to read this guide: How to Ask – slhck Jul 22 '11 at 12:57
Post Office Protocol/Internet Message Access Protocol/Simple Mail Transfer Protocol, HTTP proxy,,, Windows Vista. – user857899 Jul 22 '11 at 13:09
Please write full sentences and edit your question. Can't be that hard. – slhck Jul 22 '11 at 15:11

Usually a proxy is used to control the access only to the web (http on port 80 and https on 443). Hence you shouldn't need to configure the proxy to access any of POP/IMAP/SMTP. The proxy setting in Thunderbird will be used only when reading an email that has http content linked to it.

I would recommend that you check if secure access is mandatory for your POP/IMAP/SMTP servers and make sure to check the corresponding options such as SSL, etc.

share|improve this answer

The same way you'd do it for any program not supporting proxy - with a 'socksification' tool. However, because you use a HTTP proxy, rather than SOCKS, this is in fact very complicated.

If your HTTP proxy allows CONNECT command to your mail servers, then you can use a socksification tool directly with that. However, I have not found a free Windows socksification tool that supports HTTP proxies; ProxyCap and SocksChain do, but are not free.

If, on the other hand, your HTTP proxy does not allow CONNECT to your mail servers, the only way to get around is via an intermediate server you have access to. This is not easy to set up, and there are multiple ways of doing it. If you don't have networking experience, you probably won't succeed. To put it simply, you'd have to:

  • Manage to connect to the intermediate server, somehow. This can be different things, like SSH with dynamic forwarding or a real VPN. Either way, this connection will have to go through the your HTTP proxy. You can achieve this with a socksification tool, as mentioned above, or the application itself may support it (unlikely). You may have to change the port number of the intermediate server (e.g. to 443, to look like HTTPS) to get the HTTP proxy to allow communication.

  • Use this connection to forward your network traffic through the intermediate server. For example, if you used SSH dynamic forwarding, you can use a socksification tool (possibly the second time) to make connections go through the local SOCKS proxy opened by the SSH client. Or, if you used a real VPN, set up routes properly through the VPN.

share|improve this answer
I tried ProxyTunnel but it doesn't work, if it did work, how would I connect it to Thunderbird? C:\>proxytunnel -p -d Via -> # connects C:\>proxytunnel -p -d Via -> HTTP return code: 403 Forbidden C:\>proxytunnel -p -d Via -> HTTP return code: 403 Forbidden – user857899 Jul 22 '11 at 14:05
Sorry about the confusion; ProxyTunnel is only useful with SSH, and I think not on Windows. I've updated my answer to be more complete. – Ambroz Bizjak Jul 22 '11 at 14:13

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.