Outlook Express
Step 1: From the Tools menu, choose "Accounts."
Step 2: Select the "Mail" tab.
Step 3: Double-click the email account you need to update. (i.e. mail.yourdomain.com).
Step 4: Select the "Servers" tab.
Step 5: Check the box next to "My Server Requires Authentication."
Step 6: Click "Ok."
Outlook '98 and 2000
Step 1: From the Tools menu, choose "Accounts."
Step 2: Select email account you need to update. (i.e. mail.yourdomain.com).
Step 3: Click "Properties".
Step 4: Select the "Servers" tab.
Step 5: Check the box next to "My Server Requires Authentication."
Step 6: Click "Ok."
Outlook 2002 and 2003
Step 1: From the Tools menu, select "Email Accounts."
Step 2: Select "View or change existing email accounts" and click "Next."
Step 3: Select your Email account and click the "Change" button on the right.
Step 4: Click the "More Settings" button in the bottom-right corner of the E-Mail Accounts window.
Step 5: In the Internet Email Settings window, click the "Outgoing Server" tab.
Step 6: Check the box next to "My outgoing server (SMTP) requires authentication."
Outlook 2007
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.
Step 5: Check that the box next to "My outgoing server (SMTP) requires authentication" is checked and "use same settings as my incoming mail server" is selected.
Outlook 2010
Step 1: From the File menu, select "Info" and choose "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.
Step 5: Check that the box next to "My outgoing server (SMTP) requires authentication" is checked and "use same settings as my incoming mail server" is selected.
Mac Mail for OS X
Step 1: Open Mac Mail.
Step 2: From the "Mail" menu, choose "Preferences."
Step 3: Click the "Accounts" icon at the top of the window.
Step 4: Next to "Outgoing Mail Server (SMTP):" click on the drop-down menu and go to "Edit SMTP Server List"
Step 5: Check to make sure you have the correct SMTP server selected at the top.
Step 6: Verify that "Authentication" is set to "Password."
Step 7: If the "User Name" and "Password" fields are not set, enter your full email address as the username, and your password.
Step 8: Click "Ok."
Step 9: Close the accounts window by clicking on the red circle in the far upper left hand corner of the "Accounts" window.
Step 10: Mac Mail will ask you if you wish to save your changes, make sure to click the "Save" button.
