Suped

Summary

When sending a remarkably large email deployment, such as 6 million messages, on shared IP addresses, the need to send in batches largely depends on the specific practices of your Email Service Provider (ESP) and the established warm-up of their shared IP pools. Unlike dedicated IPs which often require a methodical IP warming process from scratch, shared IPs are typically already warmed by the collective sending of many users. However, sudden, unusually large spikes in volume, even on shared infrastructure, can sometimes trigger monitoring systems or throttling, so it is prudent to understand your ESP's capabilities. The primary concern shifts from IP reputation to the recipient's website infrastructure if the email campaign drives significant traffic.

What email marketers say

Email marketers often discuss the delicate balance between sending speed and deliverability, especially when dealing with large lists on shared infrastructure. While the general consensus leans towards trusting your ESP to manage shared IP performance, concerns about volume spikes and their impact on sender reputation frequently arise.

Marketer view

Marketer from Email Geeks asks if batching is necessary for an unusually large 6-million email deployment on shared IPs and, if so, how many batches would be ideal.

17 Jun 2020 - Email Geeks

Marketer view

Marketer from Email Geeks suggests that a 6-million email send on shared IPs should generally be acceptable, indicating that the ESP's infrastructure is likely robust enough.

17 Jun 2020 - Email Geeks

What the experts say

Experts emphasize that while shared IPs are managed by the ESP, large or unusual sending patterns still warrant careful consideration. They highlight the importance of communication with the ESP and list quality, even when relying on shared infrastructure. The discussion often turns to the broader context of a sender's overall email program and how unusual volumes fit within it.

Expert view

Expert from Email Geeks recommends directly consulting with your ESP for confirmation, as the necessity for batching heavily relies on how well the shared IPs have been warmed up to handle the proposed volume.

17 Jun 2020 - Email Geeks

Expert view

Expert from Email Geeks advises the sender to speak with their ESP to facilitate load balancing for the large deployment, reassuring them that the send will likely proceed without major issues.

17 Jun 2020 - Email Geeks

What the documentation says

Official documentation and industry guides provide foundational knowledge on shared versus dedicated IPs, IP warming, and best practices for large email sends. They generally confirm that shared IPs are managed for collective reputation, but also highlight risks associated with sudden, large, or poorly managed sends, even within a shared environment. The core principle remains consistent: maintaining a positive sender reputation is paramount, regardless of IP type.

Technical article

Documentation from IPXO states that shared IP addresses do not necessitate a warm-up procedure, but they inherently provide less direct control over the IP's overall trustworthiness compared to dedicated IP addresses.

22 Mar 2025 - IPXO

Technical article

Documentation from Webbula warns that excessively rapid email sending from a new IP address can lead Internet Service Providers to suspect spam-like activity, particularly when coupled with low engagement or increased spam complaints.

22 Mar 2025 - Webbula

13 resources

Start improving your email deliverability today

Get started