Visvanath Ratnaweera

Oder den Test in einem Kiosk-System wie Safe Exam Browser http://safeexambrowser.org durchfuehren.

I didn't canvas against nginx, that is what the OP wanted. See the subject line.

To talk of "vast majority" one needs numbers. The world-wide numbers, 34.53% Apache : 16:65% nginx, tell a different story. See the October stats from Netcraft I've provided earlier.

About the huge reservoir of knowledge, in addition to the links I've provided, a Moodle forum search, https://moodle.org/mod/forum/search.php?id=5, gave me plenty of discussions, amoung others:
- https://moodle.org/mod/forum/discuss.php?d=319812
- https://moodle.org/mod/forum/discuss.php?d=314248
- https://moodle.org/mod/forum/discuss.php?d=283326
- https://www.digitalocean.com/community/tutorials/how-to-install-moodle-via-git-with-postgres-nginx-and-php-on-an-ubuntu-12-04-vps
- https://moodle.org/mod/forum/discuss.php?d=234656
- https://moodle.org/mod/forum/discuss.php?d=205218

99.9% Moodles running Apache? From where did you get the number?

Amoung all the web servers, Apache has a share of 35%: http://news.netcraft.com/archives/2015/10/16/october-2015-web-server-survey.html.

You have to decide on one: Apache or nginx.
- Apache https://docs.moodle.org/en/Step-by-step_Installation_Guide_for_Ubuntu
- nginx https://docs.moodle.org/dev/Install_Moodle_On_Ubuntu_with_Nginx/PHP-fpm, https://docs.moodle.org/en/Nginx and more detailed info on https://moopi.uk/course/view.php?id=4.

Hi
> but if it's to and from gmail (which the OP said it was),

I can't see where OP talked of sending e-mail _to_ Gmail(?).

My understanding is that his Moodle is relaying e-mail through some Google business mail, casually formulated, sending _from_ some Google service. (Which is, strictly speaking not true. The envelope From: is usually the Moodle server itself.)