We've got an odd one that I hope the gang can help with.
I've got 2 users having the same issue. Basically, they aren't receiving mail from certain users. For example, Bob can send an email to both Angie and Brian. Angie gets the mail, but Brian doesn't. I've checked Bob's sent file and he's got both email addresses correct. It's not delivering into their junk or trash folders. And Bob doesn't get any bounce back.
My second user, Mickey, is having the same issue. Mail is sent to multiple people but he doesn't get his copy.