Mail won't send or receive email on your Mac

Why it happens

Mail stops when it can't log in to your email account. That often happens after you change your password elsewhere, or when your provider changes its security rules. A macOS update can also leave Mail needing to sign in again.

How to fix it

1. Open Mail and look in the sidebar next to each inbox for a warning triangle or a lightning bolt.

   Mail

2. Click the icon to read the message. If it mentions a password or login, the account needs signing in again.

3. Quit Mail, open Internet Accounts in System Settings, click the account and type its current password.

   Internet Accounts

4. Not sure of the password? Sign in to your provider's website. If that fails, reset the password there first.

5. Can receive but not send? The sidebar won't show a warning for that. Choose Window, then Connection Doctor, to see whether the incoming or outgoing server is failing.

   Mail›Window›Connection Doctor

6. If an alert says Mail cannot send the message, re-enter the account's password in Internet Accounts. Or, if the alert lets you choose a server, pick the account's own outgoing server and send again.

7. If nothing works, remove the account in Mail's settings under Accounts with the minus button, then add it back.

   Mail›Settings…›Accounts

Still not fixed?

1. Add the account back from Internet Accounts with Add Account…, pick your provider and sign in. Then turn on Mail for it.

   Internet Accounts›Add Account…

2. If one mailbox shows wrong or missing emails, select it and choose Mailbox, then Rebuild. It can look empty for a while as it downloads again.

   Mail›Mailbox›Rebuild

3. Restart your Mac and check for a macOS update in General, then Software Update.

   General›Software Update

4. If webmail works but Mail still won't, check with your email provider. If they find nothing wrong, contact Apple Support.