Mail not working on a Mac? 7 fixes to try

2 min read · 7 steps · Updated 2 October 2026

When Mail on a Mac stops sending or receiving, the cause is the connection, the account at your provider, or the way the account is set up in Mail. These checks separate the three.

Menu names are from recent versions of macOS, where the settings app is called System Settings.

Step by step

1. Check the internet connection

   Open a website in a browser. If the connection is fine, wait a few minutes and try Mail again. Short outages at the provider are common.

   Done

2. Click the status icon

   A warning triangle or a lightning bolt next to an inbox in the sidebar, or at the top right of the window, means that Mail cannot reach the account. Click it to read the reason.

   Done

3. Act on the message

   Network offline or cannot connect to server: switch off VPN or network monitoring software for a test. Login failed or password rejected: the password was changed or the provider wants a new sign-in. Enter the current password, or ask the provider why it is refused.

   Done

4. Test with webmail

   Sign in on the provider's website, for example icloud.com or gmail.com. If mail works there, the account is fine and the set-up in Mail is the problem. If it fails there too, the provider has to help. Also look for a notice about new terms that you must accept.

   Done

5. Check the storage of the mailbox

   Control-click the account's mailbox in the sidebar and choose Get Account Info. If the storage at the provider is full, no new mail arrives. Delete large messages and choose Mailbox, Erase Deleted Items, or move messages to a mailbox under On My Mac.

   Done

6. Check the provider's status page

   Apple, Google and Microsoft publish status pages for their mail services. An outage there explains errors on all your devices at once.

   Done

7. Remove the account and add it again

   Open System Settings, Internet Accounts, select the account and remove it. Then add it again and pick the right provider from the list. Mail stored at the provider is downloaded again. Messages kept only under On My Mac are not affected.

   Done

Good to know

If mail arrives and messages seem to be missing, check the Junk mailbox, your rules under Mail, Settings, Rules, and whether a filter is active in the message list.

If only sending fails, look at the outgoing server: Mail, Settings, Accounts, Server Settings.

The same problem on the phone: iPhone not sending emails: 6 fixes to try.

In short: Internet, status icon, act on the message, webmail test, storage, status page, remove and add the account.