Warming up your sending domain and IP are very important. You should take the time to warm them up before sending large volumes of emails so that you can build a positive reputation with ISPs and improve your future email deliverability.
- Why do we need to warm up sending domain and IP
- How to do an email domain and IP warm-up
- Recommended warm-up speed
- Top tips to help you along the way
Why do we need to warm up sending domain and IP
To build a positive reputation with ISPs, we highly recommend that you start by sending emails in small amounts and gradually increase these volumes over time to warm up your sending domain and IP. This process allows ISPs to recognize you as a sender and become more lenient with your messages.
If you do not follow this warm-up process for your sending domain and IP (e.g., send 100,000 emails from a fresh IP or unknown domain), ISPs will be surprised by this large sending volume from an unrecognized sender/IP address. ISPs may not deliver your messages to your recipients' inboxes if they do not trust you. Following the recommended process to gradually increase your sending volumes will enable ISPs to both recognize and trust you as a sender.
How to do an email domain and IP warm-up?
A good and proper warm-up is usually performed with at least four weeks of continuous sending with a daily volume increase. It means that you cannot warm up your IP with only one email campaign; it takes weeks of regular, day-to-day sending with gradual increased daily sending volume.
Recommended warm-up speed
| Day # | Recommended Sending Volume/Day |
| 1 | 100 |
| 2 | 300 |
| 3 | 500 |
| 4 | 800 |
| 5 | 1,200 |
| 6 | 1,800 |
| 7 | 2,700 |
| 8 | 4,000 |
| 9 | 6,000 |
| 10 | 9,000 |
| 11 | 13,000 |
| 12 | 20,000 |
| 13 | 30,000 |
| 14 | 45,000 |
Top tips to help you along the way
- Target your most engaged recipients during the warmup process to ensure that you see good open and click rates. For example, start with the segments that have click activities in the last 3/7/14/30 days, then move to the segments that have open activities in the last 14/30/60 days. If you don't have engagement data, use your most recent sign-ups because those users tend to be most active right after they sign up for an email list.
- Determine the number of emails you should send and the daily increasing speed. A recommended increase speed range is from 20%~50% depending on your list age, list hygiene, user engagement, complaint rate, etc. During the warmup phase, pay close attention to your campaign performances. If you are attaining good email deliverability with high engagement rates, then you can try to speed up the process. However, if you get throttled, slow it down. Starting cautiously as it's very hard to repair a bad reputation.
- Maintain warm-up across ALL ISPS. It’s important to remember that you must maintain a steady volume during the entire warm-up period at EACH ISP. (i.e. Split up your warm-up schedule so each ISP is receiving a comparable amount of mail each day, and evenly disperse your mail to each ISP on each day of warm-up.) If not, your sending activity looks sporadic and you won’t be able to build a solid reputation.
- Please note: These sample schedules are intended to be a suggestion only. Every sender is different and contacts our email deliverability experts to help you determine the right warm-up volume and frequency for your email campaigns.