Could be, I'm not sure how the other plugins send emails, so can't say about that. I understood from reading the thread that everything used to work, and since upgrading the plugin to 0.9.3 it stopped working, but it seems like that's not correct.
Personally, I'm using the plugin on WP 3.7.1 and v 0.9.3 and everything works fine. But I'm only sending mail to localhost, no authentication.