SparkPost is a bulk e-mail delivery provider.
RFC 822 defines the standard for Internet email headers. Any header that starts with X- is a custom header.
Use an online tool such as MXToolbox to copy-paste and analyze email headers.
| # | Mail Header Name |
|---|---|
| Authentication-Results | |
| Content-Length | |
| Content-Type | |
| DKIM-Signature | |
| From | |
| List-Id | |
| List-Unsubscribe | |
| Message-ID | |
| MIME-Version | |
| Received | |
| Received-SPF | |
| Reply-To | |
| Return-Path | |
| Subject | |
| To | |
| X-Apparently-To | |
| X-Binding | |
| X-Mailfrom | |
| X-MarketoID | |
| X-MktArchive | |
| X-MSFBL | |
| X-Originating-IP | |
| X-YMailISG |