FYI: Turned on email bounce handling

Heads up that I've enabled automated email bounce handling.

Bounced emails can cause problems for both you and for everyone else at SJ.

For you, a bouncing email means that you won't be notified if someone PMs you, and if you forget your password you'll be locked out of your account.

For other users, it means their email server might flag an email from SJ as spam and not deliver it to them. One of the ways that receiving email servers identify spam is by watching which email servers send a lot of bounced email--those servers are more likely to be a spam server blindly shotgunning emails at random addresses hoping that the user actually exists. Right now ~5% of SJ emails are being rejected by the receiving email server, whereas this should really be more like <1%... hopefully this bounce handling should increase the sending reputation of our email server over time.

If SJ tries to email you and gets a bounce notification from your email server, two things will happen:

1. A notice will appear when you next login to the site letting you know that your email is bouncing and providing a link to update your email address. Instead of a notice, I'd prefer to just send you an alert email instead, but...
2. A bouncing address sometimes happens because a spammer's email account was identified and deleted by gmail/outlook/yahoo etc, so to minimize spammers on here, any accounts that bounce will immediately lose posting privileges until they update with a new email address.

The way this bounce processing happens under the covers is a bit fragile--among other problems, different email servers send different responses for bounce notifications, so infrequently a working email address will get incorrectly flagged as bouncing. For example, if you set your SJ email setup to forward to another email account, and that other email account starts bouncing messages, then your SJ email might be incorrectly marked as doing the bouncing. If this happens to you, let me know via the Contact Us button at the bottom of every page or just email support@sportsjournalists.com and we'll get it sorted out.

This functionality is built into Xenforo and I did very little other than flip a switch, but I hadn't enabled it previously because I needed to configure the email server to alert Xenforo when emails were bouncing.