Happy you've find the file and so the solutions
It would be interesting to know from anyone of avast team if they are going to remove from the code program the support to these voice, or they what to leave it....
Indeed it would! And may add a supplementary question, "If the capability remains, why not leave the checkbox choices in the user interface?"
Re editing 'EmailShield.ini' files.
Of the 6 I've done so far, I've had to locate one in a strange location, then cut and paste another with lines from a working AIS 7.0.1426 installation file into an apparently incomplete 7.0.1466 version.
This is still less work than uninstalling avast! and installing (and configuring IMAP and SMTP SSL servers in) AVG. But I do sincerely hope it doesn't get any trickier in forthcoming avast! editions.