Esendex offers customers the ability to send from shared IPs and dedicated IPs. The basic difference between these two options is explained in their names: a shared IP is a shared resource used by several unrelated senders; whereas a dedicated IP is one which is reserved for the exclusive use of one single sender.

When you are sending from a dedicated IP, you and you alone own its sender reputation. This means your ability to hit the inbox will no longer be influenced by the mailing practices of other senders but entirely dependent on your list collection and targeting practices.

If your dedicated IP address is brand new and ISPs have never received email from it, you need to start building your reputation properly with an IP warm-up.

A warm-up means you start sending a small but gradually increasing volume of emails, giving the ISPs the time needed to analyse your content, see how recipients react, and other factors involved in building a strong sender reputation.

ISPs are suspicious of large volumes of emails from a new IP address with no prior sending history (also known as a cold IP), as this behaviour is common with spammers!

It’s also important to focus on more than just the volume you send. Make a positive impression with the ISPs by focusing on active recipients who opted in to receive your emails, and who find value in the content you send. High “marked as spam” and unsubscribe rates, as well as low user engagement (low opens and clicks), are clear indications to the ISPs that your mail is going to recipients who do not wish to receive it. This can lead to mail being delivered in the Spam folder, and can also increase the length of time it takes to finish your IP warm-up.

For more information about the warm-up procedure, check our article “How do I warm up my IP?”

Dedicated IPs are typically recommended if you are sending over 100,000 emails per month. It is recommended to send a minimum of 3,000 emails daily. If you send smaller volumes, have an irregular sending frequency, or simply don’t send email that often, Esendex Shared IPs may be a better option.

Please note: one dedicated IP is automatically assigned when choosing the monthly package for 100,000 emails or higher. ISPs recommend that a single dedicated IP handles no more than 300,000 emails a day / 9,000,000 emails a month. If you are going to exceed this, you can purchase a second, third etc dedicated IP. Upon approval of your request, the Deliverability Team will create a customized warm-up plan specifically for your email program.