First email in Inbox takes ages to open

I have set Outlook to open in Inbox and to Send & Receive on opening. However, if there is even a single mail in the Inbox, regardless of HTML, Plain Text, large or as small as 4 lines, it takes about 40 sec. to open this and then takes about 20 sec. to complete the receiving procedure for new mails. In retrospect when there is no mail in the inbox it checks up quickly for new mails.

This is a fresh copy of Outlook, with MS Office '03 duly updated, as I recently reformated and there are less than 30 mails altogether. These have been duly archived and compacted..In the Advanced Settings, COM Add-Ins is completely empty and the Add-In Manager has only Emon from NOD32 in it.

Earlier it finished everything in less than two shakes of the duck's tail!

What could be wrong?