webmail help please

[vinhwsu]

hello all,

I have problem with webmail. With an attachment, if I send from plesk mail to yahoo, or yahoo to plesk, with both, I can read the attachment. But if I send from plesk mail to plesk mail, I cann't see the attachment. What I see is the following message:

"This message was sent using IMP, the Internet Messaging Program"

Can you help me to fix this problem?

Thanks