Jenkins cannot find smtp.gmail.com
email, gmail, jenkins
Solution
Java Mail does not support the use of HTTP Proxies; http://www.oracle.com/technetwork/java/faq-135477.html#proxy
However;
If your proxy server supports the SOCKS V4 or V5 protocol (http://www.socks.nec.com/aboutsocks.html, RFC1928) and allows anonymous connections, and you're using JDK 1.5 or newer and JavaMail 1.4.5 or newer, you can configure a SOCKS proxy on a per-session, per-protocol basis by setting the "mail.smtp.socks.host" property as described in the javadocs for the com.sun.mail.smtp package. Similar properties exist for the "imap" and "pop3" protocols.
As an alternative, you could setup an MTA on the local machine such as postfix or sendmail which will accept connections on localhost and may be more configurable than Java to punch through the proxy configuration.
Note: If you company blocks connections on non-http ports (eg anything apart from 80, 8080, 443) then you may need to find another solution, perhaps getting some support from your local system administrators.
Also; If you want to be clever, you can setup a (Temporary) socks proxy using ssh with the following command;
ssh -D 9090 <remoteserver>
This assumes that the remoteserver has unrestricted access, and you can point connecting clients that can cope with SOCKS to localhost : 9090.
Problem
I am running Jenkins on RHEL6 in a tomcat container. My computer is behind my company proxy, which I have defined in the Plugins configuration tab. I can download plugins so that works (at least for port 8080, that is). I am now trying to configure an SMTP server. I am trying with my localhost SMTP server but cannot get it to work, so I decided to debug first using something that should work (gmail). I have set SMTP server to "smtp.gmail.com" and port "465". I have tried with ports 25, 587 too. I get response: ``` javax.mail.MessagingException: Unknown SMTP host: smtp.gmail.com; nested exception is: java.net.UnknownHostException: smtp.gmail.com at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1932) at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:638) ``` What could be wrong?