What is Send time optimization and How do I send optimized emails?

Send Time Optimization is a ML based Algorithm to detect a users preferred time to receive an email. Basis on user's historic behavior and data, Raman - Netcore's AI engine will predict and send at the preferred open time for a user, resulting in better open rates. These requests will be executed across 24 hour cycle.


Criteria for enabling Send time Optimization

STO Model Considers campaigns for last 3-month

To Activate STO on Panel, following criteria should be satisfied:

  • Minimum of 3 months of data on the panel
  • Overall Open Rates of those Campaigns should be greater than 5%
  • Minimum user count on the panel should be greater than 10,000

How do I send STO emails?

Once enabled on an account, all that is needed to be done to send requests with STO is to pass a STO true parameter on the API request or the SMTP Header ("sto": true) . Raman takes care of the magic post that.
Please refer to the following screenshot for a sample request:


Sending over a 24 hour cycle

Email request with STO is sent on the preferred time identified over a 24 hour period. So in essence if you send in the email request, the requests could be send at any point time till the next day. For Example, say an email to [email protected] is to be sent through STO. The request is placed at 2 pm, John would receive the email at any time that is identified as preferred till 2 PM day after, say 1 PM.

Note: Not all request sent through STO can be identified with the right time. This could because the user does not have sufficient behavior history and/or is a new user. Such users are tagged as unpredictable and are communicated at the end of the 24 hour cycle.

All STO requests are tagged as following on the reports:

  • STO Applied: the request is for STO
  • STO Predictable: Users preferred time is predictable and communication is sent at the time.
  • STO Unpredictable: Users preferred time is unpredictable and communication is sent at the end of the cycle.

Reports for STO campaigns can be simply viewed across the panel by simply using STO Tags, applicable on engagement reports, funnels and all.



Webhooks will be sent when mail are sent to email id, i.e, the predicted time and not the request time and it contains the actual delivered time.