Mail Connection Doctor can help explain why the Mail app isn't sending or receiving email on your Mac.
If you can’t send or receive email on your Mac, you can use Mail Connection Doctor to learn more about the issue. Mail Connection Doctor checks the status of your Internet connection and each of your email accounts.
Open the Mail app, then choose Window > Connection Doctor from the menu bar.
If you're connected to the Internet but Mail Connection Doctor shows a red dot next to one or more of your accounts, check the Details column for more information about the issue.
If Mail couldn't log in to the account
If the Details column of Mail Connector Doctor shows that Mail couldn't log in to your account:
- Your email service may be experiencing a service outage. Contact them or use their status webpage to make sure that their mail service is online.
- The password for your email account may be missing, or it may no longer be valid.
If Mail couldn't connect to the server
If the Details column of Mail Connector Doctor shows that Mail couldn't connect to the server:
- The settings for your email account may not be correct. Check Mail preferences to make sure that your email account settings are up to date. You can use the Mail Settings Lookup tool to check the settings for many email providers or get them from your email provider.
- A network firewall may be blocking connection to your email service. This can happen after installing third-party firewall software, or when you're on a different network that doesn't allow the necessary email connections. If you're connecting from your corporate network, contact your corporate IT department for help. If you're connecting from somewhere else, such as a coffee shop or Internet cafe, check with their staff.
If you need more detail
If you need more information about the issue:
- Click the Show Detail button to open a drawer showing basic communication between the Mail app and your email service. If the drawer is empty, click Check Again to start another check. You can copy data from this drawer and paste it into another app for easier viewing. Messages that contain "ALERT" come directly from your email provider.
- Select the Log Connection Activity checkbox to cause Mail to generate detailed logs of its communication with your email service. To view the logs, click Show Logs. To stop logging, deselect Log Connection Activity.