I’ve disabled the function that allows visitors to subscribe to comment notifications on a post without leaving an actual comment.  This is to save me the constant barrage of bounced messages in addition to not having my server listed as a possible spammer because of all the e-mail being sent out to invalid addresses.

I don’t know why, but increasingly spammers have been entering bad addresses into that notification system.  There are thousands of them in there right now, and they’re entered on almost every post going back to the beginning of 2003.

My first guess is that automated bots are seeing that form field and, because they’re only bots and generally quite stupid, believe it to be either related to submitting a comment or related to sending e-mail.  Neither is true, of course.

Since the addresses they’re entering are invalid, however, any real comment left on those posts generates an outbound notification to every subscribed address, and that means I’m getting bounces to all of these nonexistent accounts.

I doubt the change I’ve made will hurt anyone.  The only difference now is that you must leave a comment in order to receive comment notifications from a post.  You’ll no longer be able to sign up for notifications only without submitting feedback.

I’ve not looked at how extensively that function has been used since I implemented it, so I can’t even say if it’s been used legitimately at all or if it’s only full of these errant spammer addresses.  I can say this: I’m going to remove all of those subscriptions if I can.  There doesn’t appear to be an easy way to manage the comment notifications or to run a report to see how many are subscription-only versus commented-and-subscribed.  I’ll do my best to filter through them so I can clean up all the bad addresses that are in there right now.