STO Improves Email Opens in More Ways than One

Most Internet Service Providers (ISPs) set limits on the number of emails they receive from a sender during a specified period of time. They do this to prevent server performance issues. Exceeding those limits may result in the ISP throttling the delivery of email to various recipient inboxes.  It may also trigger a soft bounce deferral. This results in the email arriving in inboxes much later than the actual send. It can even cause hard bounces.

Marketers often send an email campaign to the entire target audience all at once. This increases the possibility of exceeding ISP limits.  To circumvent these limits, they can throttle the campaign by sending emails to small audience batches over time.  Although this helps improve deliverability, each batch is randomly grouped together. This in turn increases the chance that an email arrives in a recipient’s inbox at an inconvenient time, like late at night when the person is asleep.