[Mailman-Users] Preventing accidental resubscription

[Darrell Burkey]

I've had a client ask me how they can keep track of who unsubscribes 
from their lists so that they don't accidentally resubscribe the same 
address at some later point.

Seems like just keeping a list of addresses of the unsubscribe notices 
that come in would be reasonable but they made the point that they would 
  have to go through all the bounce notices as well to indentify 
addresses that were unsubscribed due to excessive bounces as well.

I've done a fair amount of searching around and haven't seen the topic 
raised although it seems likely that it would have been.

Unless anyone has any better advice I'm consider writinging a hack to 
copy unsubscribe addresses to a file that can be checked before 
subscribing someone.

How do others handle this?

Thanks in advance from downunder.