patch
https://app.mailivery.io/api/v1/campaigns//signature
Create or update the email signature for a single mailbox (campaign).
- If no signature exists, Mailivery will create one.
- If a signature already exists, only the fields you provide will be updated.
Use this endpoint to keep mailbox signatures in sync with your CRM, HR system, or onboarding flows.
400Validation error – missing or invalid fields
401Unauthorized – Invalid or missing API token
403Team not found or not accessible
404Campaign not found or not accessible
500Signature update failed due to server error