What Is an SMTP Smart Host?

SMTP smart hosts are used to send email messages

An SMTP (Simple Mail Transfer Protocol) smart host refers an intermediary server, usually provided by your Internet service provider, that you can use to send your outgoing email. Some companies also offer smart host services on a chargeable basis.

Background

When you send outgoing email your email goes to its destination via the SMTP protocol. Your Internet service provider will usually provide you with details of its SMTP server so you can configure your email software or server.

Benefits

Destination email servers generally prefer to receive incoming email via a verifiable smart host to reduce the volume of spam email they receive. Internet service providers usually require customers using their servers to provide authentication details so their servers cannot be used without authorization.

Options

Network administrators managing email servers have to ability to use a smart host or use their servers to send mail directly -- usually it is best to use a smart host to ensure mail does not bounce back from some mail servers. Home users who are unlikely to run their own email servers usually have their email software configured to always use their ISP's smart host.

References

• Microsoft: Managing Smart Host