To connect Yahoo mailbox to E-Warmup, you can follow these steps:
To connect your Yahoo Mail to E-Warmup, you’ll need to create an App password. Simply head over to your mailbox account and click “Manage your account”

Next, go to the Security tab and click "Create app Password" from External Connections tab:

Generate an app password and save it.

Use this app password to connect your mailbox to E-Warmup.

DONE !!