Authorisation faild #MBR1212

just downloaded EM and when I try to email from Yahoo a box pops up with

Authorisation faild #MBR1212

I have deleted the account and manually added email and removed from username but still no luck

Hello Jackie,

Could we please ask if you have activated the two-step verification on Yahoo? Yahoo has recently made the two-step verification mandatory for all accounts. To set it up, please sign into your Yahoo Account Info page Go to Account Security, turn the two-step verification on and follow the necessary steps to activate it. You will then need to create an app-specific password for eM Client as a 3rd party application. Go to Manage app passwords, click on Other application, fill in eM Client and you will get your password. Use this password for your Yahoo account in eM Client.

More info about enabling two-step verification:
More info about app specific passwords:

The should stay in the username.

Please let us know if this has resolved your issue.