Iterable provides the option for clients to use dedicated IP's and shared IP's. If you prefer to use a dedicated IP, this means only your company is responsible for your IP reputation. It also means that you will need to warmup your brand new, cold IP's over a period of 4-8 weeks by gradually adding email volume to a new IP address. Think of IP reputation like a credit score. A good reputation is achieved over time after you've proven to Internet Service Providers (ISPs), that you're a good sender that sends quality, engaging and non-spam emails.
IP Warm-up Best Practices
Take your time
Never try to rush through an IP warm up. When ISP's see email volume spikes from a new IP address, they will assume that you are a spammer who jumps from IP to IP, running email scams as Ethiopian princes trying to wire you money. Sending too many emails through a new IP too quickly will result in being marked as an unknown sender, getting rate limited, and being blocked from the inbox. Your sender reputation will be damaged forever.
It is crucial to gradually build up your email volume on a new IP address over a period of 4-8 weeks. A slow and steady ramp up will help you develop a good reputation, which will prevent your emails from getting blocked, filtered and rate limited.
Begin with most active and engaged users
Start your warm up by sending to your most engaged subscribers, typically new signups or those who have opened or clicked an email in the past 30 days. These subscribers will be more likely to engage with your emails, signaling to ISP's that you're a sender who sends emails that people want to receive. Add in older segments gradually in chunks 10-25% of your total send. The purpose of your warm-up period is to send to subscribers who are least likely to bounce or mark your emails as spam.
Consistency is key
The more consistent you can be with your sending frequency and volume, the faster you will be able to warm up your IP and establish a positive sending reputation. Do not start and stop the warm up process. This will make the IP warm up process longer.
Step-by-Step IP Warm-up Plan
What to Expect During IP Warm-up
Bulking is when an ISP accepts your email but places it in the bulk or spam folder. This can occur during IP warm up, especially if you're sending to AOL, Yahoo or Gmail. Bulking should clear up within a couple sends with positive engagement metrics. The key is to keep sending emails on the new IP.
Blocking may also occur if your subscribers are not engaging with your emails or if you are going over the daily volume caps recommended in the warm up plan. Try segmenting your list and sending to the most engaged users and scaling back on volume. Slowly ramp back up on the ISPs that are blocking your emails. The key here is to continue sending.