# Mail proxy to 3rd party using ssl **URL:** \ **Category:** NGINX\ **Created:** [September 3, 2013, 7:22am UTC](https://www.ruby-forum.com/t/mail-proxy-to-3rd-party-using-ssl/246135 "2013-09-03T07:22:59Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Rafa\_F](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Post date:** [September 3, 2013, 7:22am UTC](https://www.ruby-forum.com/t/mail-proxy-to-3rd-party-using-ssl/246135/1 "2013-09-03T07:22:59Z")
I am setting up nginx as POP3 mail proxy to two 3rd party mail servers. Different domains, one of them uses SSL. Since I do not have that 3rd party’s SSL certificate I use my own company certificate in nginx. That cert is properly signed but obviousy belongs to another domain (our domain). If I connect to the non-ssl server through nginx all works fine (port 110 on nginx and 3rd party server). If I connect to the ssl domain through nginx (port 995 on nginx and 3rd party server) I seem to not get a response from the 3rd party server. The authentication routine on connection establishment is properly called by nginx (correct uname/pw) and it returns that the user is OK (correct 3rd party IP address is returned as well). Using the email client without proxy works fine, meaning: uname/pw are correct. Questions: - Is such configuration possible at all (ssl to 3rd party server without having that server’s certificate installed on nginx)? - Is nginx in this configurtion a man-in-the middle? Could that be a problem? - Any idea how to further debug? Thanks, Rick Posted at Nginx Forum: > **[mail proxy to 3rd party using ssl](https://forum.nginx.org/read.php?2,242473,242473#msg-242473)** > > I am setting up nginx as POP3 mail proxy to two 3rd party mail servers. Different domains, one of them uses SSL. Since I do not have that 3rd party's SSL certificate I use my own company certificate in nginx. That cert is properly signed but obviousy... ---
**Author:** ![rmombassa](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/e480ec/32.png) [@rmombassa](https://www.ruby-forum.com/u/rmombassa)\ **Post date:** [September 3, 2013, 2:02pm UTC](https://www.ruby-forum.com/t/mail-proxy-to-3rd-party-using-ssl/246135/2 "2013-09-03T14:02:01Z")
Hello! On Tue, Sep 03, 2013 at 01:22:36AM -0400, rmombassa wrote: > If I connect to the ssl domain through nginx (port 995 on nginx and 3rd > having that server’s certificate installed on nginx)? > > - Is nginx in this configurtion a man-in-the middle? Could that be a > problem? > - Any idea how to further debug? The main problem you are facing right now is that nginx doesn’t support SSL mail backends. And as far as I understand the description of what you are trying to do, it’s a MITM, and it’s not going to work unless you control clients and can convince them to accept your certificate. But it’s likely not a problem as you already have everything working with non-ssl backends. – Maxim D. > **[nginx: donation](http://nginx.org/en/donation.html)**