SMTP Relay
A service that routes your outgoing emails through a third-party server for improved deliverability and tracking.
SMTP relay services act as intermediaries between your email platform and the recipient's mail server. Instead of sending directly from your mail server, your emails are routed through the relay service's infrastructure.
Popular SMTP relay services include Amazon SES, Mailgun, and SendGrid. These services offer dedicated IP addresses, delivery optimization, and detailed analytics that improve deliverability at scale.
For cold email, SMTP relay is useful when you need more control over your sending infrastructure or when you're sending at volumes that exceed what Google Workspace or Microsoft 365 can handle (typically 2,000 emails/day).