I have a bunch of people at work that I usually email as a group. I had all m contacts in my Gmail, so they were automatically synced with the phone when i got it. In the people app, I made a group with all of my work contacts that I email usually. I've been told that some people haven't been getting the emails, and I finally figured out why. Everyone I have a facebook contact for, as well as a regular contact, I linked together when I got the phone. What I didn't know, is that anyone that had an email address connected to their facebook profile was automatically synced, and made the Primary contact for each person. So, a lot of the people that have facebook, had their school email address on their profile, and therefore that email address was made primary. So everytime i sent out a group email, it got sent to that address, instead of their work email that I already had in their contact. I just manually went into each contact, and made sure the correct primary address was selected. Just an FYI for anyone with work contacts that also have facebook profiles.