Enabling IMAP in Yahoo mail
Hotter can use your Yahoo email account to send all outbound emails.
We use the IMAP protocol to detect lead answers, bounces, out-of-office replies, etc.
Check that IMAP is turned on:
Sign in to Yahoo Mail.
Go to your "Account security" settings.
Allow apps that use less secure sign in.
Getting app password for Yahoo mail
Getting app passwords in Yahoo mail (by Yahoo)
App passwords in Yahoo mail (by Lifewire)
IMAP settings in Yahoo mail (by Lifewire)