You will typically search for "t21p-e2.bin" in the following scenarios:

: The bootloader file that instructs the phone how to start the recovery process.

: On the Yealink T21P E2, recovery mode is usually triggered by holding the Speaker button while reconnecting the power cable. Important Safety Warning

: Some users use recovery mode to replace restricted carrier firmware (such as those from Rostelecom) with standard Yealink firmware to use the device with any provider. How to Use the Recovery File

: Install a tool like Tftpd64 or PumpKIN on your computer.