Mail appears to send but nobody receives

[pmd]

When I send out group emails it goes to the outbox and it appears to send, but nobody actually receives my email. Individual emails send, but not group emails. Help and Thanks

 

[DavidE]

If you're using WLM, there can be problems with Group emails.
Here is one recent thread about this (with a link to a previous thread):
http://www.sevenforums.com/browsers-mail/391944-live-mail-not-sending-group-emails.html

If you're not using WLM, what email client program are you using ?