Question : Oulook distribution list does not send to everyone in the list

I have looked every where for a solution to this problem. I have a user with several distribution lists in his Outlook 2007, with email addresses to individuals across the country. When he sends an attachment to individuals in the list that reside in a certain province, they receive the email but the attachment is stripped from the email for some reason, but everyone else in the list got the email and the associated attachment.

I have never heard or seen of this before. Any ideas?

Answer : Oulook distribution list does not send to everyone in the list

It might be a rule or some firewall/spam setting.  Here's the top things to check from this link (http://social.technet.microsoft.com/Forums/en/exchangesvradmin/thread/0274b188-16c4-4a07-a745-f3d95d2a6b9d)
1. I would look at your anti-virus anti-spam settings. Someone might have set up a scanning rule to strip attachments or something like that.

2. "Use Cashed Exchange Mode"

But from this link (http://office-outlook.com/outlook-forum/index.php?t=msg&th=93455/) it sounds like a bug in 2007.  The main thing from here is to try plain-text (doesn't make sense, but MS told them so)