Smart Host
Also known as: Relay host, smarthost
A smart host is an intermediate mail server that relays email on behalf of another server, often to improve deliverability.
A smart host is a mail server used to route outgoing email. Instead of a company's internal server sending emails directly to the recipient (which might get blocked due to residential IP ranges or poor reputation), the internal server passes the mail to a "smart host" first.
The smart host is typically a professional email service provider or ISP server with a high reputation and proper authentication records. It takes the message and delivers it to the final destination.
Using a smart host allows businesses to offload the complexities of deliverability, IP warming, and bounce handling to a dedicated infrastructure provider.
Related Terms
Dedicated Server(Dedicated IP)
A dedicated server is a private email server with its own IP address that only your company uses to send email. It gives you direct control over your sender reputation and delivery results.
Learn more →Deliverability(Email Deliverability)
Deliverability is how often your emails land in the inbox instead of spam or getting blocked. Strong deliverability means people actually see what you send and can act on it.
Learn more →Shared Server(Shared IP)
A shared server is an email server and IP address that many companies use to send their emails. Your messages go out from the same place as other senders, so you share the same reputation.
Learn more →Email Appending
Email appending is when you use a third party to add email addresses to your existing customer records based on other details like name or postal address. It is risky because these people did not ask to hear from you, which often leads to spam complaints and poor deliverability.
Learn more →