thanks a lot for your reply... we don't know actually if/which the sender email address used have a SPF policy
Anyway, your comment remided us that we have the email server for our domainame located elsewhere, not on the same cloud server where our Mediawiki is installed (and pointed trough the same domainame for which we have modified DNS accordingly).
Said this, do you think such a configuration could be the reason of the weird behaviour we're experiencing ?
In that case, what about this:
Do you thinkit could be the way to go to set thing correctly ?
Thanks again for your kind support
By the way, in the meantine we tried to add $wgUserEmailUseReplyTo = true; to LocalSettings.php and like thatwe add a little improvement: like that it now works for @gmail.com and @yahoo.com, but it is still not working for @hotmail.com, @live.com, @libero.it, @virgilio.it, ...