Cannot Send Attachments is ACT! 6.0 Email

[DoItOutdoors]

I have a user on my network at work which has 2000 Pro on his system and outlook as his email box.
ACT! 6 is installed and he cannot send or receive attachments.
When I send him an email with an attachment, it shows a paper clip in his mailbox but when you click it, it disappears. I need Help!

 

[MFDnNC]

Do you mean Outlook express - Tools - Options - Security untick the attachments box