[rt-users] getting MSMTP to work

[SSzretter]

I am having trouble getting MSMTP to work (which I have working on a
previous install).   I followed these instructions:
http://requesttracker.wikia.com/wiki/Msmtp

It works from the command line, if I echo pipe in to msmtp.

However, I do not see anything in my msmtp.log when RT is supposed to
be sending a message.
I have rt set to debug logging, and in the rt.log, I see evidence that
it looks like it is looking at sending a message, but no output that
says it actually did send it or if it failed.

Is there another log, or some other logging to enable?

Thanks!