FastMail: Unable to Send Emails — Two-Step Authentication Fix

Problem

You've added your FastMail account to Airmail but can't send emails. You may see authentication errors or the emails stay stuck in the Outbox.

Solution

If you have Two-Step Verification (2FA) enabled on your FastMail account, you need to create an App Password specifically for Airmail.

How to Create a FastMail App Password

1. Log into FastMail via web browser (fastmail.com)
2. Go to Settings → Privacy & Security → Integrations (or Settings → Password & Security)
3. Under App Passwords or Third-party apps, click New App Password
4. Give it a name like "Airmail"
5. Copy the generated password

Update Airmail with the App Password

1. Open Airmail
2. Go to Settings → Accounts
3. Select your FastMail account
4. Replace your regular password with the App Password you just generated
5. Save and test sending an email

IMAP/SMTP Settings for FastMail

If needed, use these manual settings:

• IMAP: imap.fastmail.com, Port 993, SSL
• SMTP: smtp.fastmail.com, Port 465, SSL