How many IP addresses do I need to send emails?

I often get asked, how many IP addresses do I need to successfully inbox. There is no one-size-fits-all approach, unfortunately.

PowerMTA is brilliant when it comes to handling multiple IP addresses for your sending needs. I have seen PowerMTA setups and configs where the client used over 200 IP’s in order to relay 100-150k emails a day. His inbox rates where shocking. Let me explain why more sometimes is less.

Using too many IP’s can be a risk and have a negative impact on your reputation. Using multiple IP’s for the wrong reasons, may raise a red flag with ISP’s, resulting in your email landing in the clients Junk folder, or to be filtered out completely.

  • Snowshoe Spamming – is a spamming technique where a wide range of IP addresses are used to spread out the spam send rate and or load. Using a wide range of IP addresses makes it difficult for ISP’s to successfully identify the spam resulting in some of the spam to slip through.
  • Waterfalling – is when multiple ESP’s are being used to send email. In this case, each ESP is using it’s own block of IP addresses. Spammers use one ESP to clean their lists, also called scrubbing, and another to send the actual marketing email. This technique is used by spammers and gray mailers.
  • IP hopping – is simply using one set of IP addresses today, and next week you use new ones. ISP’s might throw you into the category of Snowshoeing or Waterfalling. If for some reason you have to change your IP’s, make sure they get warmed up properly, by relaying only a few mails per day through them. It takes a very long time to build a proper reputation for IP’s.

So how many IP addresses are right for me you ask. Good question 😉

I have seen clients send 2-3 million emails a day using 1 IP addresses with a successful inbox rate. The important factor here is, how quick do you need your emails to be delivered? If you need to inbox 5 million emails within an hour, you sure going to need more than 1 or 2 IP addresses and the correct software and infrastructure. In order to determine how many IP’s you need is actually very simple. You need to monitor your sending logs and reputation. ISP’s will throttle your email based on your sending reputation. Going through your logs will also give you some insight, why and who is throttling you. You may also want to have a look at the IPS’s postmaster pages. They are normally a good start to see and understand how many emails you can relay.

I also recommend using different IP addresses for different mail flavours. I.e

  • Marketing messages
  • Transactional messages
  • Newsletters
  • Old or in-active lists

There are positive and negative reasons for using multiple IP addresses when it comes email delivery. This all solely depends on you’re needs and situation. I hope some of the above will help you determine how many IP’s you should use.


8 thoughts on “How many IP addresses do I need to send emails?”

  1. Good Article, I think that the best method you have mentioned is waterfalling its grey Hat and not risky as Snowshoe and doesn’t waste a lot of time like IP hopping in warming up new IPS every time. But How does ISPs can detect you in waterfall method if you use different servers from different Hosts?

    1. With patterns. If you’re going to clean your list with ESP 1, then use ESP 2 to send another mail, using the same from and reply, ISP’s can pick that up. They then just might think you are a spammer and block your mail.

      I do not recommend waterfalling. There are services that can scrub your lists, however, these services cost far more than just using an ESP to send out a mail shot to do the same.

      In the end, you want to email from the same source/IP at all times. This way ISP’s get used to what and how much you’re sending and it will improve your delverability over time. This off course will only work if you’re relaying legit email.

  2. We use about 120 ip’s but are struggling with our reputation. We send about 30.000 to 50.000 emails a day. Do we need so many IP addresses?


    1. Geoffrey, this all depends. 120 IPs for 30-50k does seem to be a lot.
      Hit me up on the contact page, I will gladly have a look at your setup and we can take it from there 😉

  3. personal hello.
    do not know much but would like to know the cost for shipping two million (2,000,000) of emails per day.
    how many IP’s do I need?
    can someone send me a budget of Power MTA + Dedicated Server + Instesrpire?
    thank you

    1. Hi Christiano.

      Please take a look at the page I have attached herein.

      Is your list of 2million optin? If yes, then we can get this going quicker otherwise, we will need to go through a list cleaning process.

      one more thing, for greater deliverability, you will have to start slow and ramp up slowly so that the ISP’s do
      not block you.
      Here is an example on how to ramp up aggressively
      Day 1 5,000
      Day 2 10,900
      Day 3 15,000
      Day 4 20,300
      Meanwhile. take a look and let me know if we can work on this.



  4. Hello,

    I have a PMTA4 and Server with /27, (,,…..30) so this all ip in my server as a Additional Ip and main IP of the server is,
    So i want to send a first 5000 email only with ip (bind with domain is ; after completing that email,
    I want to send a Second email only with another Ip is (bind with domain is ; after completing that email…
    So on……

    so i need a 30 smtp with 30ip and 30 domain in PMTA.

    How can i do that with my Powermta4.

    if you want PM me via mail :
    Skype : david.fanny8

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