but I check no other AV installed
Not just currently installed, but also previously installed, some elements may remain after an uninstall that are detected by avast. So did you have another AV previously installed in this system ?
I doubt it is a virus as it would be strange for it to subjectively select only the email provider and not the main scanning element of avast.
Is the Internet mail provider active, left click the avast icon and check the list of providers if the Internet Mail is greyed out it isn't active, you could manually start it from here. You will be asked if you want the changes to persist, click Yes.
If that doesn't resolve it (which I think unlikely) then the only thing I can suggest it to reinstall. Uninstall, reboot, install, reboot.
It would probably be best to download the latest version of avast and save it to your HDD, somewhere you can find it again. Use that when you reinstall.
Edit: Checking a little further if this error is a windows one, 10104 = The procedure call table is invalid. If this is correct it could be a bad install, hopefully a reinstall as above should help.