Cannot send emails from Outlook

Follow these steps on Outlook for Mac for each affected @shaw.ca account.

1. Confirm Outlook is online
   1. Open Outlook on the Mac.
   2. On the Outlook menu (top left), make sure Work Offline is not checked.
2. Check Internet/network connection
   1. Open a web browser and confirm normal access to websites.
   2. If on a company or public network, try a different network (home Wi‑Fi or mobile hotspot) to rule out firewall restrictions.
3. Turn on SMTP authentication (common cause for POP/IMAP accounts that suddenly stop sending)
   1. In Outlook, go to the Tools menu and click Accounts.
   2. In the left pane, select the @shaw.ca account.
   3. Under Outgoing server, click More Options.
   4. In the pop‑up menu, select the authentication type required by Rogers/Shaw (typically something like “Use Incoming Server Info” or “User Name and Password”).
   5. Enter the correct username and password if prompted, then save/close.
   6. Try sending a test email from that account.
4. Verify outgoing server (SMTP) name and port Rogers/Shaw may require a specific SMTP server name, port, and SSL setting. If these are wrong, sending fails even though receiving works.
   1. Still in Tools > Accounts, select the @shaw.ca account.
   2. In the Outgoing server box, confirm the server name exactly matches what Rogers/Shaw provides.
   3. If Rogers/Shaw gave an alternative SMTP server (for example, for use outside their network), enter that instead.
   4. Save and test sending again.
5. Check for firewall or ISP blocking of SMTP If sending works on another network (for example, mobile hotspot) but not on the usual connection, the ISP or local router firewall may be blocking the SMTP port.
   1. Ask the ISP or network admin if SMTP ports for the Rogers/Shaw server are blocked.
   2. If they provide an alternative SMTP server or port, enter it:
      • Tools > Accounts
      • Select the @shaw.ca account
      • In Outgoing server, enter the alternative server name/port they give.
6. Re‑enter credentials and account details
   1. Tools > Accounts.
   2. Select the @shaw.ca account.
   3. Confirm the email address, username, and password are correct.
   4. If Rogers/Shaw require SSL or a non‑default port, make sure those options match their instructions.
7. If still failing, remove and re‑add one @shaw.ca account as a test Before removing, ensure mail is stored on the server (IMAP) or backed up if POP.
   1. Tools > Accounts.
   2. Select one @shaw.ca account and remove it.
   3. Add it again using the settings from Rogers/Shaw, making sure SMTP authentication is enabled as in step 3.
   4. Test sending.

If none of the above resolves the issue and sending fails from both Outlook for Mac and other clients using the same SMTP settings, contact Microsoft support and provide details that business accounts on a different server work, but @shaw.ca SMTP fails only in Outlook for Mac with correct ISP settings.

References:

• I can't send or receive messages with Outlook for Mac
• I can't send or receive messages in Outlook for Mac
• I can't send or receive messages in Outlook
• Why am I not able to receive emails which I used to on my outlook mac. I can send emails without any issues. - Microsoft Q&A
• my outlook has stopped sending emails. They are locked in the outbox. I am receiving emails perfectly normally. - Microsoft Q&A
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