Scheduling Parameters
With scheduling, you can send large volumes of email in queued batches or target individual recipients by specifying a custom UNIX timestamp parameter.Using the parameters defined below, you can queue batches of emails targeting individual recipients.
Info
Emails can be scheduled up to 72 hours in advance. However, this scheduling constraint does not apply to campaigns sent viaMarketing Campaigns.
This parameter allows SendGrid to begin processing a customer's email requests before sending. SendGrid queues the messages and releases them when the timestamp indicates. This technique allows for a more efficient way to distribute large email requests and canimprove overall mail delivery time performance. This functionality:
- Improves efficiency of processing and distributing large volumes of email.
- Reduces email pre-processing time.
- Enables you to time email arrival to increase open rates.
- Is available for free to all SendGrid customers.
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Cancel Scheduled sends by including a batch ID with your send. For more information, check outCancel Scheduled Sends!
When passingsend_at orsend_each_at please make sure to only use UNIX timestamps passed as integers, as shown in our examples. Any other type could result in unintended behavior.
Danger
Using bothsend_at andsend_each_at is not valid. Setting both causes your request to be dropped.
To schedule a send request for a large batch of emails, use thesend_at parameter which will send all emails at approximately the same time.send_at is aUNIX timestamp.
1{2"send_at":14093485133}
To schedule a send request for individual recipients; usesend_each_at to send emails to each recipient at the specified time.send_each_at is a sequence of UNIX timestamps, provided as an array. There must be one timestamp per email you wish to send.
1{2"to": [3"ben@example.com",4"john@example.com",5"mikeexampexample@example.com",6"example@example.com",7"example@example.com",8"example@example.com"9],10"send_each_at": [1409348513,1409348514,1409348515]11}
To allow for the cancellation of a scheduled send, you must include abatch_id with your send. To generate a validbatch_id, use thebatch id generation endpoint. Abatch_id is valid for 10 days (864,000 seconds) after generation.
1{2"to": [3"ben@example.com",4"john@example.com",5"mikeexampexample@example.com",6"example@example.com",7"example@example.com",8"example@example.com"9],10"send_at":1409348513,11"batch_id":"MWQxZmIyODYtNjE1Ni0xMWU1LWI3ZTUtMDgwMDI3OGJkMmY2LWEzMmViMjYxMw"12}