How to manage multiple emails from 1 inbox

We get a lot emails from people with multiple email addresses (like 3-5) who are finally starting to get fed up with having to check that many inboxes.

Luckily it’s 2012, and there are easy ways to simplify this, particularly in Gmail. Here’s how you can have a) multiple emails forwarded to the same Gmail inbox, b) send emails From either of those addresses right in that same inbox, and c) automatically reply From the address an email was sent To.