So I just spent the last 30 minutes updating my music mailing list. Wow! That was depressing! Basically, I added back in all possible known email addresses for all individuals on the list to find out which ones bounce back as undeliverable. From the undeliverables, I'll know which addresses to trash from the list. In the past, I've kind of ignored the "failure notices", as Gmail calls them, when emails cannot reach a particular recipient (IE: an email address no longer exists).
It wasn't an astronomical number of failure notices - somewhere around 20 or so - but it's still enough to make you do a double-take. The question becomes: am I actually failing at this?