how to overcome mail port bloackage

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PackElend
Posts: 12
Joined: December 11th, 2004, 12:10 pm

how to overcome mail port bloackage

Post by PackElend »

Hallo,
I would like to pick up the discussion held in Thunderbird also with Port Blocked.

My office blocks email ports but allows 443 via cooperated proxy for https traffic analysis.
I'm wondering if i could setup a proxy server on my NAS to make Thunderbird to connect to this proxy via https before trying to connect to an email provider standard ports to get or send emails?
I found many proxy help on: How to bypass web URL filtering service to access blocked websites (proxy) [closed] but a lot of it is outdated.

btw TB's Webmail add-on isn't maintained anymore
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tanstaafl
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Joined: July 30th, 2003, 5:06 pm

Re: how to overcome mail port bloackage

Post by tanstaafl »

https://ssimo.org/blog/id_014.html
http://hacking.elboulangero.com/2015/12 ... h-ssh.html
https://wesharethis.com/2017/07/dynamic ... erver-ssh/

I'd look into configuring a SSH tunnel as a SOCKS server if you don't think that would get you into trouble when somebody notices that traffic. I'd assume they will. Another potential risk is some network monitoring software might think your PC has been infected with malware and is calling home.

If you have to use a HTTP proxy https://superuser.com/questions/302922/ ... proxy?rq=1 and https://superuser.com/questions/472757/ ... ect=1&lq=1 might give you ideas about using it for other protocols. You might try the 32 day trial of proxifier from http://www.proxifier.com

I know very little about this area. My first reaction would be to browse the forum of whatever email provider you are using to see if somebody else did something similar, and to ask some co-workers if they are doing something similar (perhaps using a different email client).
PackElend
Posts: 12
Joined: December 11th, 2004, 12:10 pm

Re: how to overcome mail port bloackage

Post by PackElend »

thx for tips.
As the company allows to install 3rd party VPN software to allow to remote access services provided by citrix, NetNordic SHIELD or PulseSecure. So may it allow SSH tunnels.
Would it also be possible to realize it by means of a SSL tunnel, as described here: http://translate.google.com/translate?h ... &sandbox=1 or https://el-tramo.be/smtp-http-proxy?
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tanstaafl
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Joined: July 30th, 2003, 5:06 pm

Re: how to overcome mail port bloackage

Post by tanstaafl »

No. A SSL tunnel requires the web site to have a proxy server. https://dzone.com/articles/what-is-ssl-tunneling

The idea behind the SSH tunnel is to create a Socks proxy server that Thunderbird can use to communicate with the email server. The mail server communicates with the proxy server as if it was the email client. You don't need anything extra on the mail server. That is what makes the technique useful.

https://en.wikipedia.org/wiki/SOCKS
PackElend
Posts: 12
Joined: December 11th, 2004, 12:10 pm

Re: how to overcome mail port bloackage

Post by PackElend »

will do as soon as I'm done with my Nextcloud installation on my Synology NAS [-o<
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