Problem while sending Email using MAPI(C++)

Hi Guys
I am sending emails(local and external) using MAPI (C++ application)in
Pocket PC 5.0 but
sometimes my emails remains in \Windows\Messaging folder and does not appear
in Pocket PC Inbox (local emails) or outbox(external emails). I can see a
file corresponding to every email sent by my application in
\Windows\Messaging folder.

Can you please help me what could be the reasons? Am I forget to flush
somethings?
What I noticed that if I stop the messaging (Inbox)application and start it
again then all message apears.

Thanks in advance

Regards,
-Santosh