Symptoms
- New emails don't appear even though they've arrived on other devices
- Mail app shows a red exclamation point or error next to an account
- Sending emails fails or gets stuck in the Outbox
- Manually clicking 'Get Mail' doesn't retrieve anything new
Likely causes
- CommonA sign-in or authentication issue with the email accountPasswords or security settings changed on the email provider's side can break the connection.
- PossibleIncorrect or outdated server settings for a non-iCloud accountSome providers occasionally update their required settings.
- CommonMail app needing a restart to reconnect properlyThis resolves many temporary sync glitches.
- PossibleAn internet connectivity issue affecting Mail specifically or generallyWorth ruling out with a broader connectivity check.
- PossibleA large attachment or corrupted message stuck in the queueThis can block subsequent sync activity until resolved.
What to do
- Check for a red exclamation point next to the account in Mail's sidebar, which usually indicates a specific error you can click to read.
- Confirm your internet connection is working normally by checking another app or website.
- Quit and reopen Mail to force a fresh connection attempt.
- Check System Settings > Internet Accounts (or Mail's own Accounts preferences) to confirm the account is still properly signed in.
- Remove and re-add the email account if sign-in issues persist, especially after a password change on the provider's side.
- Check if the email provider requires an app-specific password (common for accounts with two-factor authentication).
- For non-iCloud accounts, verify server settings against the provider's current documentation.
- If a stuck Outbox message is blocking sync, try deleting that specific draft/message and sending again.
Tools and parts
- None required
When to call a pro
This is a settings/account issue you can resolve yourself; contact your email provider's support if account-specific settings are unclear.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.