Stunnel

Today I want to suggest a very interesting uility to tunnel your smtps connections. The software works as “gateway” binding a smtp connection and connecting to an smtps server.

It’s very useful to give smtps connections to devices that normally can’t connect with SSL/TLS, such as Exchange SMTP relayhost, some printer’s fax2mail or other embedded systems.

The software supports POP3s too at the same way.

You can download stunnel from here: https://www.stunnel.org/downloads.html

Here it’s a configuration file for gmail smtps server:

; SMTP/POP3 Configuration for Gmail
output = gmail.log
cert = stunnel.pem
client = yes 

[ssmtp] 
accept = 4650
connect = smtp.gmail.com:465 
[spop3] 
accept = 9950
connect = pop.gmail.com:995

So you have to configure your client to connect to stunnel machine, on the configured port.

For example if you have the mail client and stunnel on the same pc, with that conf file, you can use this parameters to connect:

smtp – localhost:4560
pop3 – localhost:9950

Thanks to everyone works to solve that kind of issues 🙂