Attachment Name issue in Incomimg Mail

Hi,
I am using DTS SendMailTask to send email with attchment. I am giving
FileAttchment as 'E:\test\task.txt' in FileAttachment porperty of
SendMailTask and sending it to my email id. but after receiving email
attchment showing like 'E__test_task.txt' instead of only 'task.txt' and in
send folder it is showing 'task.txt' only.
I am using OutLook profile to send emails through DTS, and exchange server
is POP3. But if i configure outlook to use Micrsoft Exchange Server then this
issuse is not coming.
Can u please reply why this is happening with POP3 server, i need to use
POP3 only.

Thanks
Vinit