Bouncing Emails

[Kat]

When a new user signs up and they enter a phoney email address it bounces back to me. To my website email. The main email I use for the forum and my site. I suppose that is fine, because I can then know that their email address is phoney and delete that user.

When a member subscribes to a thread....wanting to know when a reply is posted...and eventually their email address changes or whatever, their old account isn't valid anymore, I get their email the board tried to send them, bounced back into my account. I get many of these.

Is there something I can do about this, where if it bounces it deactivates their account until they provide a new email address that works? Or should I go in and deactivate their username, and delete their email address? I'm unsure how to proceed with this.

I've tried PMing the members to change their email addresses, but it just keeps getting worse and worse, and I honestly don't want to change my email address on file with the forum/site, cause people always email me questions about the forum, etc.