The decision to acquire more dedicated IPs hinges on a combination of factors, most notably email volume, reputation management, and infrastructure requirements. Experts and marketers agree that high-volume senders (generally exceeding 50,000-100,000 emails per month) benefit from dedicated IPs to control their reputation and avoid the negative impact of shared IP environments. Consistency in sending patterns, the types of mailbox providers (with Gmail being less sensitive), and infrastructure limitations (such as failover concerns) also play a significant role. However, experts caution against using dedicated IPs for low-volume sending, as they lack an established reputation and require careful warming up. Before adding IPs, it is important to understand the root cause of deliverability issues, such as rate limiting or content-related problems.

Email marketers generally agree that dedicated IPs become necessary when senders reach high email volumes and want more control over their sender reputation and deliverability. The specific volume threshold varies, but often cited figures range from 50,000 to 100,000 emails per month, or over 1 million per day. The type of mailbox providers, consistency of sending patterns, and the need for failover capabilities also influence the decision. Isolating your email traffic to protect your reputation from the negative impacts of shared IPs is a key driver. Infrastructure concerns from allocating only one IP for high volume are also frequently raised.

Experts emphasize that simply adding more dedicated IPs is not always the solution for email deliverability issues. One expert notes it could help but questions why the ESP isn't preventing rate limiting. Another suggests that more IPs may not solve the problem if rate limiting is content-related and instead recommends investigating the root cause and improving email practices. Furthermore, experts caution against using dedicated IPs for low-volume sending due to the lack of an established IP reputation, and emphasize the importance of warming up new IPs gradually to build a positive sending reputation.

Email service provider documentation consistently suggests that dedicated IPs are beneficial for senders aiming to manage their own reputation, maintain control over their sending activities, and isolate themselves from other users. A high sending volume, often cited as over 50,000 emails per month, and consistent sending patterns are key indicators for needing a dedicated IP. These IPs allow senders to establish and maintain their reputation independently with ISPs, and tools like Google Postmaster Tools can be used to monitor sending reputation.