Utilities
Send Single Email
Send one-off transactional email outside of campaigns with attachments
POST
Path Parameters
No path parameters
Query Parameters
string
required
Your SmartLead API key
Request Body
string
required
Recipient email address
string
required
Email subject line
string
required
Email body content (HTML or plain text)
string
Sender email address. Either
fromEmail or fromEmailId is requirednumber
ID of the sender email account. Either
fromEmail or fromEmailId is requiredstring
Display name for the sender (optional)
string
Reply-to email address (optional)
array
Array of attachment objects (optional). Each attachment requires:
filename(string): Name of the filecontent(string): Base64-encoded file contentmimeType(string): MIME type of the file (e.g., “application/pdf”)
Response Codes
Success
Request successful
Bad Request
Invalid request parameters or malformed request body
Unauthorized
Invalid or missing API key. Check your authentication.
Not Found
The requested resource (campaign, lead, email account, etc.) does not exist or you don’t have access to it
Validation Error
Request validation failed. Check parameter types, required fields, and value constraints.
Rate Limit Exceeded
Too many requests. Please slow down and retry after the rate limit resets.
Internal Server Error
Server error occurred. Please try again or contact support if the issue persists.
Service Unavailable
API is temporarily unavailable or under maintenance. Please try again later.
