bad or changed mail addresses

[Harald Brueckner <brueckner @ caesar . respublica . de>]

Hello,

I have a question regarding wrong or old email addresses on a list.

Is there a way to check if mails to ppl on my list produce errors?
What I do now is to read the mails which come back because of delivery
problems and if I come accross a specific address many times, I remove it
manually from the list.

How do other people handle that problem? I don't want addresses on my list
which are no longer valid and the subscriber simply forgot to unsubscribe.

Thanks in advance,
   Harry