Yeah, this is very frustrating. People seem to change e-mail addresses much too often. This is where you set up a free e-mail address, and have that address forward to your actual POP mailbox. This way, you give people your free address to everyone, and it stays permanent. Genealogy is a subject that really comes alive with alot of people involved.
People move around alot.
And with the ever changing face of the net, there are going to be a number of times that people will move their sites and e-mail addresses. I think everybody should have some sort of free web-mail so their addresses don't change. The sites are a little different since service varies so greatly across the different services. Angelfire is pretty good. Fortune city is the pits.