If you have Windows NT Mail essentials SMTP options In the Mail essentials configuration, go to the Mail configuration node and select properties. In the general tab, select the 'Options' button. This dialog allows you to configure relay and forwarding restrictions. 2. In this dialog you can set-up which mail server will be allowed to relay mail through Mail essentials. If your machine is running on separate machine, you will have to specify the IP of your mail server here. In addition, specify any domains that you send out mail on (i.e. that appear as senders in the sender field) In the 'Allow mail from' edit box, enter the domains and their mail server IP that you wish to send mail for, for example 'mycompany.com'. If you have other domains that you send email from, or other companies you wish to allow to send email via your mail server, add their domains as well. The ones that are not listed will not be allowed. Please note that if you enter just the domain name in the 'Allow mail relay from' field box with no IP, spammers can easily mimic your domain name thus entering the IP is important for the appropriate anti relaying protection. Note: If you don't list your own domain, no mail will be received!