I've been having problems lately with an internal MTA connecting to an external one that apparently serves the libvirt list. E.g. I recently responded to "[PATCH v2 4/4] libxl: Add a test suite for libxl option generator", which includes the xen-devel list. The response made it to xen-devel, but I received the following wrt the libvirt list The attached file had the following undeliverable recipient(s): Information about your message: Message log tag: 661753 Number of send attempts: 1 Time of initial send attempt: 06-16-14 17:11:53 Transcript of session follows: Command: EHLO victor.provo.novell.com Response: 550 TLS negotiation failure Seems like a certificate problem on the victor host. I'm trying a different smtp server for another data point in my report to internal IS&T folks. Thanks for your patience. Regards, Jim