Twilio SendGrid IP Warmup API
The Twilio SendGrid IP Warm Up API allows you to gradually increasing the volume of mail sent with a dedicated IP address according to a predetermined schedule. This gradual process helps to establish a reputation with ISPs (Internet Service Providers) as a legitimate email sender. SendGrid can automatically warm up dedicated IP addresses by limiting the amount of mail that can be sent through them per hour. The limit is determined by how long the IP address has been warming up.