On my setup, gmail-smtp-in.l.google.com works perfectly. See logging below.
If you get "Failed to connect to mail server", I would suspect a virusscanner or firewall on your system, or a blocking of port 25 by your ISP.
See
http://wiki.sabnzbd.org/firewalls-and-virus-scanners for some general information.
As you installed Kaspersky IS, I would suspect that. Easy test: de-install and remove Kaspersky completely (no, de-activating does not solve it), and try again.
Code: Select all
2015-02-26 07:28:42,990::INFO::[api:683] Sending testmail
2015-02-26 07:28:43,113::DEBUG::[emailer:80] Connecting to server gmail-smtp-in.l.google.com:25
2015-02-26 07:28:43,482::DEBUG::[emailer:93] Non-SSL mail server detected reconnecting to server gmail-smtp-in.l.google.com:25
2015-02-26 07:28:43,650::DEBUG::[emailer:107] TLS mail server detected
2015-02-26 07:28:44,652::INFO::[emailer:150] Notification e-mail succesfully sent