I've got Membership installed in a WPMU/Buddypress environment (WP 3.3.1, BP 1.5.4, Membership 3.0, WPML 1.3.0). At the moment I only have the free subscription level active, and registration seems to work as expected. However, the activation email isn't sent out at all.
I've scoured the internets for others with this problem, and they all seem to point to SMTP config issues. I'm pretty sure this isn't an SMTP/server config for 2 reasons: 1) I don't see any trace of an email even attempted to the recipient in Postfix logs 2) Other notifications (friendship requests, messages, etc.) all get sent out as expected. I don't see anything in my error logs, either. I'm going to change the log levels to NOTICE for a bit and see if that turns up anything suspicious (and I'll report back here if it does).
Is anyone else seeing this behaviour? Any help on this would be much appreciated. I find Membership is a great plugin, and just that alone makes my WPMUDEV subscription worthwhile (let alone some of the other great plugins I got from here) - you have saved me weeks of programming time. Thanks!