I honestly don't think it has anything to do with Outlook full or express....altough"push" uses some kind of strange "mail" system to provide the updates.
Waldo, you are not right... There must be some avast! mail scanner running on computer, otherwise the PUSH update can´t work.
The PUSH technology enables ALWIL Software to start iAVS update on customers computers immediately when new update is released. How to do that? Use e-mail message! There´s no "strange "mail" system to provide the updates"... ALWIL Software sends e-mail message and mail scanner of avast! (Internet Mail or Outlook/Exchange privider) checks if the message contains the "start iAVS update now!" command (special characters in message header), shortly said. If yes, the iAVS update starts. If not, the mail scanner scans the message for viruses.
To mantra:Yes, it works - if the provider Outlook/Exchange isn´t disabled for some reason.