When you add a dedicated IP address to your Mandrill account, you can also optionally warm up the IP. Mandrill warms up a dedicated IP by gradually increasing the percentage of your mail sent via the dedicated IP over the next month. This allows ISPs to get to know you as a sender and the type and volume of email you send.
There are three ways to warm up a dedicated IP address. When you first add a dedicated IP for your account, check the Start Warming Up IP Immediately box. If you've already added a dedicated IP address, follow these steps to warm up an existing IP, or warm up an IP using the Mandrill API.
Warm up an Existing Dedicated IP Address
- Go to the Add Ons page.
- Under Add Ons, locate your dedicated IP address and choose Warm up IP from the Actions drop-down menu.
- In the dialogue box that appears, click the Yes, warm up IP button to continue.
Warming-up a dedicated IP address is typically a good idea if you regularly send more than about 5,000 emails per day at least three (3) times a week. If you're sending at lower volumes, you generally wouldn't need to pre-warm the dedicated IP address.
If you have more than one dedicated IP, Mandrill will send the rest of your mail over your other dedicated IPs during the warm up period. If you have only one dedicated IP, Mandrill will send the rest of your mail over our shared pool of IPs during the warm up period.
You can switch an existing dedicated IP into warm-up mode at any time. This is useful if you want to reduce the traffic that an existing IP is sending and then slowly ramp it back up over time.