Hi,
Just an idea for a feature:
Right now one SG login maps to one email address that mail is forwarded to.
How about letting users create "aliases" per login so that they can manage multiple destination email addresses by logging into SG once.
For example, user ID "abc" can have an alias "abc" manage their Hotmail account, alias "abcy" manage their Yahoo account and so on.
This probably requires significant changes to the Web front end, but the changes to the database schema probably won't be that widespread.
Just my 2 cents