Add portal name to SMTP test email for better identification

[david-poindexter]

Description of problem

The current implementation of the SMTP test email has no identifying text to help know which DNN instance (or site within the instance) it is coming from. This has forever been annoying for those managing multiple DNN instances/sites.

Description of solution

Add from [Portal:PortalName] to the subject line of the SMTP test email.

Description of alternatives considered

n/a

Screenshots

n/a

Additional context

n/a

Affected browser

• Chrome
• Firefox
• Safari
• Internet Explorer
• Edge