Yes I have read your posts, there have been a number of threads where this was a symptom (no body text) and the solution that worked for them. Do a forum search for UseAlternateRtfSyncing and see if there is something there that replicates your problem.
However, I can't give a categoric assurance that this is the solution, as there may be other factors, like the email program used, not to mention your avast version (probably server edition). Since this possible solution was given by Technical a very experienced user, I would certainly try it.
Unfortunately since you don't have control of the avast settings you can't do that, then someone who has access will need to try the possible fix. The avast4.ini may be in a different location to the standard, that depends on how avast was set-up, try a search of your system and see if you can find avast4.ini.