If your phone displays "No Service" or "SIP Registration Failed" and the indicator light is orange, the phone may have lost its connection to the phone system due to an outdated configuration. This article explains how to resolve this issue.
Information on how to install the Mitel Connect application.
Troubleshooting steps for Voicemail problems. Particularly for forwarded numbers.
Troubleshooting steps when unable to get past the login screen on the Mitel app.