Allow specifying the SMTP FROM command / bounce address in EmailService

[justinedelson]

Required Information

• AEM Version, including Service Packs, Cumulative Fix Packs, etc: any
• ACS AEM Commons Version: any
• Reproducible on Latest? yes

Three years ago, I wrote some bad information on a forum post at https://forums.adobe.com/thread/2332589. In response to a question about how to specify the SMTP FROM address (which is a theoretically distinct concept from the From address header in the email), I said that this wasn't possible in AEM. I was wrong. In my defense, the way that this is explained in the Apache Commons Email documentation is confusing (at least to me). Commons Email refers to this as the "bounce address". See https://commons.apache.org/proper/commons-email/userguide.html#Handling_Bounced_Messages.

It's totally possible to specify this on a org.apache.commons.mail.Email object via the setBounceAddress() method. We just don't support setting this via the EmailService service. Let's fix that.

Expected Behavior

Should be possible to specify the bounce address.

Actual Behavior

Can't do it :(