Currently, Yahoo Mail API/IMAP service strongly recommends third-party applications, like Canopy, to use their OAuth-2.0 authentication flow to access a Yahoo Mail user’s account.
Unlike other email providers like Gmail and Outlook 365 who make their OAuth-2.0 authentication flow public (which makes software development easier and faster), Yahoo has an internal review process it must perform before it allows a third-party applications to access its OAuth-2.0 APIs.
We are in the process of getting approval from Yahoo to use their OAuth-2.0 authentication flow.
As soon as we are given access and are able to implement those authentication changes, we will work on migrating all Yahoo Mail accounts that are connected to Canopy to the new OAuth-2.0 authentication flow.
In the meantime, you will need to use a less secure method to connect your Yahoo Mail account to Canopy. We anticipate this to be a temporary measure while we work on getting Yahoo Mail OAuth-2.0 approval.
How to connect your account
Before you connect your account to Canopy, log into Yahoo go to Settings >Account Info.
Then go to the “Account security” section and enter your username and password.
Once you’re in the Account security section activate the “Allow apps that use less secure sign in”
You can now connect your Yahoo Mail account to Canopy.