Setting up multiple addresses

This is really a general question
When we have users whose name changes due to marriage or divorce what is the best way to keep two address open during a certain period.
Our address format is Name.FirstName@domain.com
If I have a user whose email address was Doe.Jean@domain.com changing to Todd.Jean@domain.com Can I keep the two addresses active. I don't think nicknames work in this case. I tried testing and ConsoleOne wouldn't accept the ".".

Any advice would be greatly appreciated