HUB server is not relaying mail until 1st mail is not send to smart host

I have created a receive connector on a HUB server for relay the mail from an Oracle application server.Hub server is receiving the mail and sending to smarthost then only it is picking the new mail from Application. Suppose Hub server is receiving the mail from application server at 10:00:00 then it is sending mail to smarthost at 10:00:05 and then it is picking the mail from application server at 10:00:06.
Please give you valuable comment on this.

Regards,
Kashi