Your Mac can send email but new messages just stop showing up. Almost always it is one of five things: the account went offline, the incoming (IMAP) server settings are wrong, a junk filter or rule is hiding the mail, the mailbox is full, or the local index is corrupt. Do these in order and stop when new mail appears.
1. Check the account is actually online
A lightning-bolt icon next to a mailbox in the sidebar means that account is offline. Click Mailbox > Take All Accounts Online. If it flips back to offline immediately, your Mac cannot reach the mail server — check Wi-Fi, then move to step 2. Also open Window > Connection Doctor: a red dot on the incoming (IMAP/POP) row points straight at the account that is failing.
2. Quit Mail fully and relaunch
Closing the window is not quitting. Press Command-Q (or right-click the Dock icon > Quit), wait ten seconds, and reopen. This clears a stuck sync more often than you would expect. Give it a full minute after launch before deciding it did not work.
3. Verify the incoming (IMAP) server settings
Go to Mail > Settings > Accounts, pick the account, and open Server Settings. The Incoming host, username, and port must match your provider exactly. Common values: iCloud imap.mail.me.com port 993; Gmail imap.gmail.com port 993; Outlook outlook.office365.com port 993. If your provider recently forced app passwords or two-factor, an old saved password silently breaks incoming sync — delete the password field, re-enter it, and untick then re-tick Automatically manage connection settings.
4. Make sure the mail is not being hidden
New messages can arrive and immediately get filed away where you never look:
- Junk: click the Junk mailbox — a wrong filter can route real senders there. See how blocking and junk rules work.
- Rules: a rule that moves or marks-as-read can bury new mail. Check Mail > Settings > Rules — disable them all temporarily. Our guide on rules and smart mailboxes shows how to audit them.
- Wrong mailbox selected: click Mailbox > Show All Mail or the unified Inbox to confirm you are not just viewing one empty account.
5. Free up space — a full mailbox stops receiving
Most providers reject incoming mail once your account hits its storage cap (iCloud, Gmail, and Outlook all do this). Log into your provider on the web and check the quota. On the Mac side, a nearly-full startup disk also stalls sync — keep at least 10–15 GB free.
6. Rebuild the mailbox (fixes a corrupt local copy)
If one specific mailbox is stuck, select it and choose Mailbox > Rebuild. This re-downloads the message list from the server — it does not delete server mail. On a large mailbox it can take several minutes; let it finish. This is different from a search-index problem; if search is the real issue, see fixing Mail search.
7. Remove and re-add the account (last resort)
If one account still will not receive, delete it in Mail > Settings > Accounts (this removes only the local copy for IMAP accounts — server mail is safe) and add it back fresh. Our step-by-step on adding an email account to Mail walks through it. For iCloud, toggle Mail off then on in System Settings > [your name] > iCloud.
FAQ
Mail sends fine but receives nothing — why?
Sending uses the outgoing (SMTP) server; receiving uses the incoming (IMAP/POP) server. They are configured separately, so a broken or offline incoming connection stops new mail while sending still works. Check the incoming row in Connection Doctor (step 1) and your incoming server settings (step 3).
Why do I get new mail on my iPhone but not my Mac?
The account is reaching the server, so the problem is local to the Mac: an offline account, wrong saved password, a rule hiding messages, or a corrupt mailbox. Work steps 1, 4, and 6 on the Mac.
Will rebuilding or removing the account delete my email?
No, not for IMAP or iCloud accounts — your mail lives on the server and re-downloads. Only POP accounts that download-and-delete are at risk; back those up first.
My Mac is still not receiving after all of this
If the hardware might be the problem (Wi-Fi that never connects, a Mac too old for the current macOS Mail), it may be time to upgrade. We buy working and broken Macs — get a trade-in quote and browse the Apple clearance deals toward your next one.