Yahoo, iCloud, AOL, Fastmail: app passwords

These providers let mail apps in with an app password you create in their security settings.

• Yahoo / AOL: Account info → Account security → Generate app password.
• iCloud: appleid.apple.com → Sign-In and Security → App-Specific Passwords (two-factor must be on).
• Fastmail: Settings → Privacy & Security → App passwords (choose IMAP and SMTP).
• Yandex: ID → Security → App passwords → Mail.
• Zoho: with two-factor on, My Account → Security → App passwords.

Then add the account in MailFai and paste the app password.