← Glossary
Sending
What is ESP (email service provider)?
A company that sends email on your behalf, such as SendGrid, Mailgun or Amazon SES.
How it works in practice
An ESP supplies the sending infrastructure, bounce handling and often shared IPs. You still have to authenticate your own domain with it so that its mail aligns with your From address.
The common mistake
Relying on the ESP's default authentication instead of setting up your own domain.
Related terms
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