Connecting your UpMail account directly with Gmail will ensure the emails dispatched from UpMail are actually sent from your official corporate email address for optimal email deliverability. It will also display the emails dispatched from UpMail in your Gmail’s Sent folder.
In order to do that, you would need to go to My Settings and select Integration as shown below.
Once you click on Connect, you would be taken to a dialogue window, where you would be required to sign in with Google and give UpMail permission to send emails on your behalf.
Note: if you don't give UpMail this permission, you won't be able to send emails through the application. If you have connected to Gmail without giving this permission, the application would prompt you to reconnect again.
Once you have connected to Gmail, you won't need to reconnect unless you disable the connection. The connection will remain on even if you change your password or enable 2 Factor Authentication.