PROBABLE SOLUTION FOUND:
I MIGHT just have discovered the trick to it...
This problems STARTS when i delete a mail from my HTC Mail Application.
From thereon, the ActiveSync goes in a frenzy. As long as I am not deleting anything, its totally fine and the PUSH works without any random Syncs in between.
HOW I DISCOVERED THIS (of course, learnt it the hard way):
1. Configured the ActiveSync to be PUSH
2. Then, I DELETED EVERYTHING on my GMAIL - probably needed to purge my past
.
2. Sent a mail to my GMail account.
3. The mobile device received it perfectly.
4. Did nothing but keep watching the cell screen for random syncing - didn't happen
5. Then, I actually received a stupid marketing email - so obviously, I DELETED it from the cell
6. And suddenly, the Random Syncing began again.
7. So, I logged into GMAIL, saw the inbox had only my own test mail.
8. Went into TRASH, the marketing email was NOT there
9. Went to ALL, there were both the emails there.
10. Now, I selected and re-deleted this email
11. This time around, it went to TRASH
12. Sent myself another TEST Mail.
13. Got PUSHED to the mobile device
14. DID NOT delete it from the mobile device.
15 And VOILA, we probably have a solution
I do not know if this is an error with HTC's Mail Application or GMAIL's way of handling LABELS.
So people struggling with this issue, please try what I did above and see if you can get rid of random syncing.
I suggest moving the emails that you wanna delete right away into some other folder on the HTC Mail App. Then, whenever you get online, delete them from there.
Again, we can only request HTC and Google to sort this out - it was a pity that none of the support teams did anything about this issue.
CG.
EDIT:
After tinkering around more the whole night (instead of sleeping), I found that HTC Mail has issues with GMAIL labels. i installed SMS BACKUP +, which in turn created a label called SMS Backup, it put in some sms there in form of an email and guess what the continuous syncing started again. So, I removed all the LABELS AGAIN, 2 mins. later the random syncing stopped...
which makes me wonder "WTF is going on?" lol
Laters.