Hopefully someone can help with the following:

This started about 2/3 days ago. I spent a whole day at work and received no emails to my BB. At just after 5 when I got home about 16 odd emails came flurrying through, the first one with a sent time of 08.40am. Next day, again no emails to my BB all day whilst at work but when I returned home I recieved 30 something emails in the space of minutes.

I have a reasonable mobile signal everywhere at work. I have no restriction to data download each month. I have my firewall disabled on my BB. When I return home each day my BB is jumping onto my WiFi network.

The last point I made must be important - it suggests that my email will only arrive if i'm connected to an internet connection. They are not being received over my mobile network, but they have been until just very recently. My only thought was to check for a setting that allowed you to specify over what type of connection you should receive data but I couldnt find anything like this. The only other thing I tried was a soft-reset ie removing battery whilst BB powered on still.

Hopefully someone can make a suggestion.......

Thanks

When at work, does it show GPRS (or 3G with the blackberry symbol) in capitals?

It suggests to me, its not connecting to BIS on the carrier network.
(manage connections - services status. will show if BIS is connected via mobile network)

look under

options-> mobile network

for data connectivity settings