How do I install PHPMailer on a Debian/Bullseye Apache2 server

[Gary Dale <gary@extremeground.com>]

I'm using a web hosting company that pretty much limits me to using 
PHPMailer on their servers for sending complex e-mails (e.g. with 
attachments). That is working.

To get it to work, I used the zip archive from the PHPMailer's github 
page and unzipped it into the site's public directory - so that there is 
PHPMailer folder in the same folder that has the index.html file. I 
uploaded a test .php file and it sends mail.

However when I try it with my local Apache2 server, it doesn't work. 
I've got PHP working because I have another PHP script that executes 
perfectly. However the test .php file that works on the hosting 
company's server doesn't do anything on my local server. I try to load 
the page and get nothing - not even an error message.

I tried placing a copy of the PHPMailer files in the /usr/share/php 
folder and uncommented the include_path line in 
/etc/php/8.1/apache2php.ini file to ensure that the folder was in the 
path, but still no luck (various installation howtos say to make sure 
the PHPMailer folder is in the php include path).

Does anyone have any ideas on how I can get this to work? I know that 
PHPMailer at the best of times is very finicky (e.g. it creates the same 
problem (no output) if I have a space in the (optional) second argument 
for the ->setFrom or ->addAddress methods), but in this case, the file 
is identical between the hosting company's working example and my local 
test.

Nothing shows up in the various PHP logs nor in the syslog.

Thanks.