I'm using the direct mail server connection for sending mail, see Manual:$wgSMTP
For debugging mail issues, I found it very helpful to add
$wgSMTP["debug"]=1
to LocalSettings.php
to be able to see the gory details of the SMTP exchange.
These debug messages are sent through the HTTP connection before the <html> element and this might not be displayed be every browser. I could see them on Chrome using the developer console (network tab -> HTTP response).
However, there's a warning attached: setting debug will show anyone who is using wiki mail the the SMTP exchange which includes the password.
Is it possbile to redirect the debug output of the PEAR Mail module to the debug file?
Thanks!