Throttling

Throttling is the practice of restricting the bandwidth of brands to carry out operations. In emails, throttling occurs when internet service providers (ISPs) limit the number of emails a brand can send for a specified period of time. During this period, a brand receives notices of temporary delivery failures, or soft bounces. This usually happens when ISPs detect that the brand’s IP address has suddenly ramped up its sending volume, which looks spammy. ISPs then throttle the domain while figuring out whether or not the domain is a legitimate sender.