Definition of IP warm up
IP warm up is the process of gradually sending emails over a period of time in order for email service providers to establish a positive reputation regarding the IP address used in sending.
How IP warming up works?
Initially a combination of IP address and sender domain is used to check for reputation. If it doesn’t already exists, it’s suspicious until it has a proven track history of positive interactions with those emails.
Positive interactions are considered to be opens and in some cases clicks (the higher the best) and low hardbounces or spam events.
Some email providers also have thresholds for senders. For example you can not send 100.000 to yahoo email addresses in a very short time interval (~30 minutes), as you’ll start getting errors.
The warm-up plan
Note that for new lists of subscribers, it makes sense to have a more steady warm-up plan, compared to warming up a new IP address for existing emails.
- First 2 weeks only send to most active subscribers.
- Week 3 and 4 expand to email subscribers who are less active.
- Do no send to subscribers who didn’t open nor clicked in the last 6 months.
Use the following formula to grow your daily rate:
Week1: Day N = Day N-3 + Day N-2 + Day N-1
Week2: Grow with 6-10k per day, depending on total list size.
What could happened?
You might be blocked by email providers if the list isn’t engaged enough. Try using segmentation carefully for higher engagement.
Do no stop sending, even though you might see delays in delivery.
If you have a high number of complaints (spam), then you might need to consider cleaning the list. Also consider GDPR if you don’t have permissions for the list.
Always do this warm-up with someone from our system. We have access to some logs for email delivery that allows us to better monitor the evolution.