Throttling is a feature that allows you to control the sending rate of an email campaign.
ISPs place rate-limits on IPs or domains from their end based on IP/domain reputation and sending pattern of the marketers. Normally there is a upper limit for volumes originating from an IP. Throttling helps prevent exceeding these limits, which could result in deferrals/blocks/reputation drop, especially while sending high volume campaigns and/or scaling up the volume.
Follow these steps to throttle your campaigns:
1. On Step 3 of Campaign creation, enable the feature by clicking on the Throttle this campaign checkbox under Advanced section
2. Select the throttle time from the drop down:
Note - The throttling time here refers to the number of email batches (batch size of 100) to be delivered in the user-selected time duration -
For example, if a user selects 3 hours for a campaign with segment size of 18000 (i.e. 180 email batches of 100 emails each) then 1 batch (100 emails) will be delivered every minute for 3 hours (i.e. 180 minutes)