If you are receiving unsolicited calls on your Yealink W52P cordless phone(s), but those calls don't appear in your MaxoTel call history, you may be receiving "Ghost" calls on your local network.
In order to block these calls, you will need to import a special configuration file into your phone.
The configuration file can be found here:
Instructions for importing the configuration file can be found here:
Don't worry - the configuration file won't reset any of your settings. It simply changes a single hidden setting on the phone that configures it not to accept calls from anywhere but your MaxoTel service. In effect, this blocks ghost calls.
Learn more about ghost calls here: Ghost Calls