Use this glossary to understand common SendClean email, authentication, delivery, and API terms.
| Term | Definition |
|---|
| SMTP | Simple Mail Transfer Protocol — the protocol used for sending emails across the internet. |
| Term | Definition |
|---|
| DKIM | DomainKeys Identified Mail — an email authentication method that uses cryptographic signatures. |
| SPF | Sender Policy Framework — an email authentication method that specifies authorized sending servers. |
| DMARC | Domain-based Message Authentication, Reporting & Conformance — an email authentication policy. |
| API Token | A secure credential used for authentication instead of a password. |
| Term | Definition |
|---|
| Webhook | An HTTP callback that sends real-time event notifications to your application. |
| Bounce | Failed email delivery. Hard bounces are permanent failures, and soft bounces are temporary failures. |
| Suppression List | A list of email addresses that should not receive emails from your account. |
| Term | Definition |
|---|
| Rate Limiting | Restrictions on the number of requests allowed in a specific time period. |
| Base64 | An encoding scheme used to represent binary data, such as attachments, as text. |
