Avoid confusion (options):
Because you’re going to be using both accounts for a while, it would be a good idea to keep your data in one place, and not in both. Once you have verified that your calendar data and contacts are both in your new account, It would be a good idea to delete all that information from your old account.
To delete your calendar data:
You will receive a warning. Just confirm, and your calendar data will be deleted. Repeat this process for any additional calendars.
To delete your contact data:
What this will do is take all incoming mail, and send it over to your new address. Transparently to you.
Because this is so transparent, you may want to set up a filter in your new account to differentiate between messages that were sent to your new address vs your old address. This trick will be useful to pin point any accounts websites / accounts / credit cards, etc , which still have your old email address, and will prompt you to go and change those at a later time. Meanwhile, no email flow will be interrupted, or inconvenienced.
To setup the filter, in your firstname.lastname@example.org, go to your Mail Settings
Now, any mail that was sent to the old account will end up in your new mailbox, but will be tagged with a label.
Setup send on behalf of, on your new account:
In order to avoid having to keep going back and forth between your accounts, setup a “Send mail as” your old account, on your new account.
To do this:
Since you already sent out the main message, and since you can’t be sure that everyone is going to change their address-books immediately, you want to have a backup plan, so that you make sure everyone eventually has your new address. For this reason, you can setup an “Vacation Auto Responder” on your email@example.com, which informs your contacts that this email is no longer checked, and inform them of the new email address. For the lazy people, they’ll eventually get tired of the auto-responder, and will change their address-books. Even though the message will say that the email isn’t checked anymore, this is only informative to your users, as all email is already automatically being forwarded to your new address.
Step 3: Miscellaneous items.
There are a couple of items left for the migration.
If you have a Google Voice account that you would like to move over to the new address, there is a form that you would have to go through to submit that request. Google will take up to 5 business to process. If you already have a Google voice account on the new account, and you apply for the transfer, the old information will replace your new one, and this process is irreversible. Google will warn you plenty of times before submitting the request.
iPhone or Mobile Device
Since all mail and calendars are likely being synced to your mobile device, you want to make sure to change all the account pointers on your phone, to point to the new account.
In brief, the quickest way to do this, is to just change the username on your iPhone’s mail setup from oldaccount to new account, and change the label of your account to “New Gmail” or something recognizable.
In addition, add a new IMAP connection on your phone, pointing to your old gmail, so that you still have access to your old archived messages as well, without having to login and logout multiple times. Make sure you turn off your Calendar, and Contact sync on the old account, and keep them on, on the new account.
One last step is to re-sync your calendars with the new gmail account:
To do this
Remember, if you had any shared calendars, or were sharing calendars with other people, you will need to re-share those as well.