Mailplane

Mailplane can manage as many Gmail and Google Apps accounts as you need.

Mailplane lets you add different Gmail and Google Apps accounts. You can then switch between accounts without reentering your Gmail username and password.

Here's how you add an account:

Open preferences by clicking the Mailplane > Preferences menu item.

1. Click the Accounts tab
2. Optional: Click Create new Gmail account if you need to sign up for the Gmail or Google Apps account.
3. Click the plus sign below the account list
4. Double click the "email address" entry and change the email address to match your Gmail or Google Apps account email address. Examples: myaddress@gmail.com (Gmail) or myaddress@mydomain.com (Google Apps)
5. Optional: Give the account a name for easy identification within Mailplane. Examples: Business, Private etc.

Switch to your newly added Gmail account

To access your Gmail account you need to switch to it:

1. Click the "Accounts" toolbar item to open the accounts drawer (or use the View > Open Accounts Drawer menu item)
2. Select the newly added account in the list
3. Click the Switch To... button.
   Alternative: Double click the account in the list.
4. Enter the Gmail password in Authentication dialog
5. Click the Login button load your inbox.