If your customers are receiving an error message like below, there are 2 settings that may need to be adjusted.
‘firstname.lastname@example.org’ on 9/15/2006 11:11 AM
550 5.7.1 Unable to relay for email@example.com
Configure your Exchange Server to accept mail anonymously for your domain
The directions below are for Exchange 2007, but most mail servers should have similar settings.
- Please confirm that your Send Connector has Anonymous Users allowed under Permission Groups.
- Open your Exchange Management Console and access Server Configuration > Hub Transport > Receive Connectors
- Right Click on the Default (or any other Receive Connector your company uses) and choose Properties.
- Select the Permission Groups tab and ensure that Anonymous Users is checked.
NOTE: This does NOT allow anonymous users to send mail through your server, this would configure the server as an Open Relay; that would be bad. This allows anonymous users to have access to the Receive Connector so they can send mail addressed to your domain(s).
Configure your Email Client to authenticate when it connects to your SMTP server
To resolve this issue please adjust their email client to require ‘My Outgoing Server SMTP Requires Authentication’. The directions below are for Outlook 2007, but most mail clients should have similar settings.
- Open Outlook
- Go to Tools > Email Account > Change
- Click More Settings > Select Outgoing Server tab and ensure that check box next to My Outgoing Server SMTP Requires authentication is enabled.
- Click Ok and Next and Finish.