Our system automatically throttles the send of high volume campaigns in order to protect your sender reputation. This is the default large send speed and sends your messages as soon as possible, limited only by compliance with send volumes imposed by the mailbox providers (MBPs) managing the inboxes you're delivering to. For scheduled sends that aren't split tests, we send to most recent openers first to help get your emails delivered as fast as possible.
Learn more in our blog post Boost email speed and engagement.
However, you might want to control the send rate over a longer period. This can help protect your email sending reputation with big email providers. Spreading large sends over a period of time will also help ensure your customer service phone lines and resources aren’t swamped should your campaign include a telephone call-to-action.
Before you start
Things you need to know:
You must send to at least 500 contacts
Throttled sending only works if your campaign is sent to at least 500 contacts. Otherwise, your campaign is sent immediately, using the default speed.Your email report shows data as the send reaches your contacts
Reporting is available once the campaign is sent and it is updated until the send is complete. For example, you can access any reports over a 24 hour period if you've chosen a spread of 24 hours.Pausing and unpausing a campaign stops throttled sending
If you're using throttled sending and pause and then resume a campaign, the chosen time of the spread send no longer applies. This is because the remainder of the unsent emails are sent immediately upon unpausing.Throttled sending is not available for split test campaigns.
1. Enable send throttling on your account
Expand the User menu, then go to Settings > General >Account settings
For Features, check the Enable send throttling check box.
Select Save settings.
2. Send a campaign with throttled sending
When choosing your contacts and scheduling your campaign, the throttled sending options appear in step 2.
Under Choose a send time, select Immediately
Select Spread my campaign send over at least.
Expand the time drop-down menu, and choose a time period to spread the send of your campaign over.
Choose from 1 hour, 2 hours, 3 hours, 6 hours, 12 hours, or 24 hours. The send is broken down into chunks of 500 emails over the time you choose.
Alternatives to throttled sending
You can use send-time optimisation as a great alternative to throttled sending. Send time optimisation starts sending your campaign immediately or at a later scheduled date and time.
Emails are optimised to the time of individual sends to maximise open rates based on your contacts' historical opening behaviour. The campaign optimises over a period of 24 hours from the initial time of sending and will remain in the outbox until complete.
Send time optimisation isn't available for split test campaigns.