We understand that developers with higher volumes or processing time constraints need to send their messages in batches. To facilitate this we provide a batching endpoint that permits you to send up to 500 well-formed Postmark messages in a single API call. If you are sending Broadcast (bulk) messages with the batch call, use the MessageStream field to set your sending Stream.
Please note that the batch endpoint accepts up to 500 messages per API call, and up to 50 MB payload size, including attachments.
The format of the batched message is a JSON array containing multiple message requests.
Batch request examples can be seen here.
curl "https://api.postmarkapp.com/email/batch" \
-X POST \
-H "Accept: application/json" \
-H "Content-Type: application/json" \
-H "X-Postmark-Server-Token: server token" \
-d '[{
"From": "sender@example.com",
"To": "receiver1@example.com",
"Subject": "Postmark test #1",
"TextBody": "Hello dear Postmark user.",
"HtmlBody": "<html><body><strong>Hello</strong> dear Postmark user.</body></html>",
"MessageStream": "outbound"
},
{
"From": "sender@example.com",
"To": "receiver2@example.com",
"Subject": "Postmark test #2",
"TextBody": "Hello dear Postmark user.",
"HtmlBody": "<html><body><strong>Hello</strong> dear Postmark user.</body></html>",
"MessageStream": "outbound"
}
]'Similarly, you will receive a matching JSON array containing each response for the messages you sent in your batched call.
See a full list of API errors for more details.
[
{
"ErrorCode": 0,
"Message": "OK",
"MessageID": "b7bc2f4a-e38e-4336-af7d-e6c392c2f817",
"SubmittedAt": "2010-11-26T12:01:05.1794748-05:00",
"To": "receiver1@example.com"
},
{
"ErrorCode": 0,
"Message": "OK",
"MessageID": "e2ecbbfc-fe12-463d-b933-9fe22915106d",
"SubmittedAt": "2010-11-26T12:01:05.1794748-05:00",
"To": "receiver2@example.com"
}
]