Secure Computing announced on Monday a free service that allows any e-mail user to check the reputation of the domain from which they send e-mail.

Available now, Domain Health Check gives inquirers specific information about the host they use to send e-mail, according to company officials. These reputation scores, gathered by Secure Computing’s TrustedSource service that assigns a reputation score to every IP address based on its sending behavior, can be particularly helpful in pinpointing when a computer has been taken over by a botnet and used to send spam without the computer’s owner ever knowing it, they say.

TrustedSource collects IP address information from Secure Computing’s 7,000 e-mail security appliances installed worldwide that scan inbound and outbound messages.

Reputation scores work much like credit scores, with excessive sending activity – usually a sign of a spam blast – lowering the score, officials explain. Domain Health Check users also receive remediation instructions, should they suspect their PC has been taken over by a botnet.

The Domain Health Check service is part of Secure Computing’s TrustedSource portal, a Web site that provides information on global e-mail traffic patterns and volume, as well as black lists and white lists.