I have a problem i have created a application in vb.net using WEBDEV which will read/send mails from the Exchange server to the users,

right now iam facing a problem i.e..,The attachments which are with the mails are not been sent to the users

Please help me solve this issue:
1)I came to know about X-MS-ENUMATTS method but iam not able to find a single resource which will say me how to implement the catch is i send emails depending upon the time to the users say for a user 'A'
i will be sending all the emails from 1pm-4pm,the next user 'B' will start getting mails from the server from 4pm-8pm.

please help me with the solution.....

regards,
Prashanth