Step 1: From the Tools menu, select "Account Settings".
Step 2: Select your Email account and click the "Change" button.
Step 3: Click the "More Settings" button in the bottom-right corner of the E-Mail Accounts window.
Step 4: In the Internet Email Settings window, click the "Outgoing Server" tab. Ensure that the box next to "My outgoing server (SMTP) requires authentication" is checked and "use same settings as my incoming mail server" is selected.
Step 5: Click the "Advanced" tab and make sure that "Use the following type of encrypted connection" is set to "None" for the incoming and the outgoing (SMTP) port settings. Change the outgoing server port to 25 or 26 or 587.
Microsoft Outlook 2010, 2013, 2016 (PC)
Step 1: From the File menu, select "Info" and choose "Account Settings".
Step 2: Select your Email account and click the "Change" button. Click the "More Settings..." button in the bottom-right corner of the E-Mail Accounts window.
Step 3: In the Internet Email Settings window, click the "Outgoing Server" tab. Ensure that the box next to "My outgoing server (SMTP) requires authentication" is checked and "use same settings as my incoming mail server" is selected.
Step 4: Click the "Advanced" tab and make sure that "Use the following type of encrypted connection" is set to "None" for the outgoing (SMTP) port settings.
Step 5: Change the outgoing server port to 25 or 26 or 587.