Error 5.1.1 xxx@domain.com User unknown.
Explanation: Mail Cannot be Sent. The SMTP server does not recognize any of the authentication methods supported by Entourage. Try changing the SMTP authentication options in Account settings or contact the network administrator.
Account name: "<name>@domain.com"
Error: -17092
RESOLUTION
Step 1: Verify Account Settings
Start Entourage, open the account settings, and then verify that the Internet service provider (ISP) settings are correct.Step 2: Change Authentication Settings
- Start Entourage.
- On the Tools menu, click Accounts.
- Select the email account.
- Click Edit.
- Near the bottom of the dialog box, click the Click here for advanced sending options button.
- Clear the SMTP server requires authentication check box.
- Click OK two times, and then close the Accounts window.
- Move all email messages from the Outbox to the Drafts folder, and then send a test email message to someone other than yourself.
Step 3: Change the SMTP Port to 587
To change the SMTP port to 587, follow these steps:- Start Entourage.
- On the Tools menu, click Accounts.
- Open your email account.
- In the Sending Mail section of the Account Settings tab, type your account's email domain address in the SMTP server field.
- Click Click here for advanced sending options.
- Click to select the Override default SMTP port check box, and then change the port setting to 587.
- Click in the small box in the upper-left corner to close the window.
- Click OK to save the changes.
- Close the Accounts window.
- Move all email messages from the Outbox to the Drafts folder, and then send a test email message to someone other than yourself.