Fastmail

Fastmail never lets a mail client sign in with your normal password. You need an app password with IMAP access.

1. Create an app password

1. Sign in to Fastmail and open Settings.
2. Go to Privacy & Security, then Connected apps & API tokens.
3. Choose Manage app passwords and access, then New app password.
4. Name it mcp4mail and give it access to Mail (IMAP/POP/SMTP).
5. Copy the password it shows. Fastmail shows it only once.

2. The settings to use

Setting	Value
IMAP server	imap.fastmail.com
Port	993
Security	SSL/TLS
Username	your full address, e.g. jana@fastmail.com
Password	the app password from step 1

If it still does not connect

• "Authentication failed" — check that the app password has IMAP access, and that you did not paste your normal Fastmail password.
• You use your own domain on Fastmail — the server is still imap.fastmail.com; the username is your Fastmail login address.