Lisa, I assume you were still sending out Emails through your UBB.threads 7.5.x series forums using phpmailer 2.0.2.
This page shows that you were using UBB.threads 7.5.x at least until July 2017 (6 months ago): https://web.archive.org/web/20170624233802/http://forums.bellaonline.com/ubbthreads.php/forum_summary
Maybe that's part of the issue. You were announcing to all the mail servers you mailed to, that you were using a highly unsecure 2007 version of an email script. And you were sending out emails from an insecure HTTP/1.0 email server.
UBB.threads 7.6.0 (your current version, since yesterday) uses PHPMailer 5.2.22. your previous version from 48hrs ago was v2.0.2. UBB.threads 7.6.1 uses PHPMailer 5.2.25.
iirc, in late 2016, many of major email services refused to accept emails receive d by phpmailers older than at least v5 and not using ssl/tls. again, that's iirc. EDIT: See my post below this one.
Can I ask why you havent updated your discussion forum to TLS (HTTPS) yet? This may also be a reason why you are not seeing traffic. Google wont rank it very well when it is not secure, and still accepting user login/password information across http. See attached screenshot.
In addition, your website presents itself as a "LINK FARM." More than a thousand hundred links on your main forum page. See attached screenshot.
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Back on topic, the code you're looking for regarding watch list emails is in /libs/ubbthreads.inc.php Search for "_SUBJECT" or "Fill in the subject"
if wnx = "t" for WATCH TOPICS if wnx = "f" for WATCH FORUMS if wnx = "u" for WATCH USERS"
Although that section has been completely rewritten for UBB.threads 7.6.2, it is still relevant for the older version of UBB.threads which you are currently running.
Decide which WATCH LIST TYPE you want to prevent your users from ever getting emails from (even if they want to have those emails sent to them), and input an if/than clause which will prevent them from going through if the use's last visit date is greater than "NOW" - "FIVE YEARS AGO" (using UNIX TIME STAMPS). You could even wrap that whole section around your custom time if/than check.
