So I've transitioned at work, and everything has been fine... except for my email change.
I started off with joe.lastname@ and switched to jo.lastname@ when I went full-time and didn't know what my new name would be. We have google apps and I'm the admin. I went into the admin console and changed the email and name, and set it up so that anyone who emailed the old one would be forwarded to the new one (alias function). About a week ago I changed it to joan.lastname@ and disabled forwarding of the joe.lastname@.
^Bad Idea

Here's the best way: Have the admin set up a new account with the new name. Then go into the old account and use the vacation thing, but make it say something about the name change and what your new email is.
The problem with the way I did it is that my new email address is forever linked to the old one. Unless everyone who has my old email goes in and manually changes/deletes it, I'll never be rid of it. Folks will type in my new name, but google still has the old email attached. I have contacted their support but they were not helpful. They did put in a feature request to alert admins that changing the name/email of an account will continue to have it linked.
Perhaps this is a sign for me to be out and proud about being transgender.