As a sender, assigning the appropriate number of IPs is an important part of developing a positive reputation with the mailbox providers. Like warming, IP assignment is determined by a variety of factors; some of these factors include daily/weekly volume, mailing stream (marketing versus transactional/triggered), sender reputation, and ISP distribution.
The following table shows the appropriate number of IPs required to send the different email volumes successfully:
|
Total Weekly Volume
|
IPs
|
|
75,000
|
1
|
|
100,000
|
1
|
|
200,000
|
1
|
|
300,000
|
1-2
|
|
400,000
|
1-2
|
|
500,000
|
1-2
|
|
1,000,000
|
2-3
|
|
2,000,000
|
3-4
|
|
3,000,000
|
3-4
|
|
4,000,000
|
5-6
|
|
5,000,000
|
5-6
|
|
6,000,000
|
5-6
|
|
7,000,000
|
6-7
|
|
8,000,000
|
6-7
|
|
9,000,000
|
6-7
|
|
10,000,000
|
7-8
|
|
15,000,000
|
8-9
|
|
20,000,000
|
9-10
|
|
25,000,000
|
10-11
|
|
30,000,000
|
11-12
|
Note:
- Sending from more IPs than volume dictates can bring a sender’s reputation into question. Spammers employ a process called snowshoeing where they try to lessen their footprint by sending their volume over a disproportionate number of IPs. As such, it is important to only utilize as many IPs to send your mail as is required.
- Some mailbox providers have very strict limits on the amount of email traffic they allow over a specific period of time. Understanding your email list composition is a key component to understanding how many IPs are necessary to deliver your mail in a timely manner.