If your hosting provider thinks that a webmail app (which they neither 
pay for or help support) is responsible for dropping email, then you 
need a new hosting provider. Unfortunately they're the only ones who 
can help you here. http://wiki.horde.org/ICantGetMyMail

losing email according to the plesk statistic, my hosting service 
provider, bigpond send me back to horde and horde it seems don't have 
anything to do with the email issues.  I just need someone to help me 
from emails not coming through.  an example is lkleist@hjb.com, none 
of the emails from this person come through but everything else does.   
he's on the safe sender list and his emails come to my hotmail account 
and to by bigpond account, from outlook I have set up mail to to go 
directly to outlook but his emails never come through. he's a client 
and it looks unprofessional for me to use my hotmail account to get 
around this problem.  if you can't help please suggest something as 
I'm going around in circles.  thank you very much.
Jo