Outlook for Mac is not sending and receiving IMAP and POP email

Jill Ahern 0 Reputation points
2026-03-18T19:43:20.4866667+00:00

Both my husband and I are having issues with emails in Outlook for Mac, on two different computers. We have uninstalled and reinstalled, tried Classic to add the IMAP and SMTP manually, and installed updates but are still missing emails. We know that they went to the (two different) hosting servers as we can get them in webmail there. It seems this must be related to a recent change made as it has not previously been an issue. We are on the same Microsoft Business License. What can be done to address this?

Outlook | MacOS | New Outlook for Mac | For home

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  1. AI answer

    2026-03-18T19:43:45.99+00:00

    Use the following checks and fixes in Outlook for Mac for both IMAP and POP accounts:

    1. Confirm Outlook and network connectivity
    • Make sure the Mac is online and can browse other websites.
    • In Outlook, on the Outlook menu, ensure Work Offline is not checked so Outlook can connect to mail servers.
    1. Check mailbox and service prerequisites
    • If using Microsoft cloud storage (for example, Outlook.com or Microsoft 365 mailboxes in the same profile), verify that mailbox storage is not full using the mailbox storage page. If storage is full, sending and receiving will stop until space is freed.
    1. Verify each account’s server and credential settings For each IMAP/POP account on both Macs:
    2. Go to Tools > Accounts.
    3. Select the affected account in the left pane.
    4. Confirm:
      • Correct email address, user name, and password are entered.
      • Incoming server type and port (IMAP/POP) match the hosting provider’s documented settings.
      • Any required security options (such as SSL and non‑default ports) are enabled as required by the provider.
      • Outgoing server (SMTP) name/address is correct.

    If messages appear in webmail but not in Outlook, incorrect ports or SSL settings are common causes. If the account still does not work after verification, contact the hosting provider for the exact IMAP/POP/SMTP settings and required ports.

    1. Enable SMTP authentication for sending Some IMAP/POP providers require authentication on the outgoing (SMTP) server:
    2. Tools > Accounts.
    3. Select the account.
    4. Under Outgoing server, select More Options.
    5. Choose the correct authentication type and enter the same credentials used for the incoming server, if required.
    6. Check for firewall or network restrictions If both Macs are on the same network and both are affected, the ISP or local network may be blocking SMTP or other mail ports:
    7. Ask the ISP or network administrator whether ports used by the hosting providers’ SMTP/IMAP/POP servers are blocked.
    8. If the provider offers an alternative SMTP server or port, enter it:
      • Tools > Accounts.
      • Select the account.
      • In Outgoing server, enter the alternative server name/address and port as provided.

    If the laptops are used in multiple locations, note that an SMTP server that works on one network may be blocked on another.

    1. Check for required proxy settings (corporate or filtered networks) If the network requires a proxy to reach external mail servers:
    • Configure the proxy in macOS System Settings / System Preferences as provided by the network administrator.
    • After configuring the proxy, restart Outlook and test send/receive again.
    1. Confirm the mail servers are available Since messages are visible in webmail, the servers are generally reachable, but if issues are intermittent:
    • Contact each hosting provider to confirm there are no current outages or throttling on IMAP/POP/SMTP connections.
    1. If using Exchange accounts in the same profile If any Exchange account in the same Outlook profile is not receiving mail while webmail works:
    • Ensure Outlook is online (no Work Offline).
    • Check the Exchange account status under Tools > Accounts; an orange indicator shows connection issues.
    • If a specific Exchange folder is not updating, empty its cache so Outlook re-downloads items:
      1. Confirm the Mac is connected to the Exchange server.
      2. Ctrl+click or right‑click the affected Exchange folder in the navigation pane and select Properties.
      3. On General, choose Empty Cache. Outlook will re-sync the folder from the server.

    If, after these steps, IMAP/POP mail still only appears in webmail and not Outlook on both Macs, the next step is to work with the hosting providers and network/ISP to confirm ports, SSL requirements, and any recent changes to their IMAP/POP/SMTP policies, then align the Outlook account settings accordingly.

    References:

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