| Dev | https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-dev/v1/smtp/email |
| https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-dev/v2/smtp/email |
| https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-dev/v2/smtp/email/attachments |
| Test | https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-qa1/v1/smtp/email |
| https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-qa1/v2/smtp/email |
| https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-qa1/v2/smtp/email/attachments |
| UAT | https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-pp1/v1/smtp/email |
| https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-pp1/v2/smtp/email |
| https://apis-sandbox.cambridgeassessment.org.uk/ca-smtp-xapi-pp1/v2/smtp/email/attachments |
| PROD | Yet to be published |