You can configure your email account at anytime by accessing your account via webmail.
First Open Your WebMail
Next you will need to be on the WebMail home page.
This opens by default but if you've set your account to go directly to your inbox you will need to switch back to the Home screen to make changes.
If you use RoundCube click on the Webmail Home icon in the left hand side main toolbar: |
Your Webmail home screen should look something like this: