I was able to send email from our email server without any problems. But after activating "Manage mass mailing campaigns" our company mail server does not work for outgoing emails from Odoo v8 running on Windows Server 2008 R2 .
I tried all possible combinations of ports and connection security settings, but nothing works. (Yet when i test connection in outgoing server settings, "Everything seems properly set up!")
Only server which is working for sending emails with mass-mailing installed is gmail server (which we don't want to use, naturally).
When I try to send email from odoo without mass mailing module, our server still works ok.
Our email server is using default ISP config settings for debian 7.
Thanks for any help