What is the recommended maximum email volume per IP address for deliverability?
Matthew Whittaker
Co-founder & CTO, Suped
Published 16 May 2025
Updated 19 Aug 2025
6 min read
The question of the recommended maximum email volume per IP address for deliverability is common, but the answer is not a simple fixed number. Instead, it's a dynamic threshold heavily influenced by your sender reputation, the recipient's mailbox provider (ISP) policies, and your email sending patterns. There's no universal limit, as what one ISP accepts readily, another might view with suspicion.
Mailbox providers, such as Google and Microsoft, evaluate your sending behavior to determine how much email they're willing to accept from your IP address. This behavior includes factors like bounce rates, spam complaint rates, and user engagement (opens and clicks). A strong, positive reputation allows for significantly higher volumes, while a poor one can lead to throttling or blocklisting, even at lower sending rates.
The nuanced answer: it depends on your reputation
Ultimately, the maximum volume you can send from an IP depends on your recipient engagement and the trust you've built with ISPs. If your recipients consistently engage with your emails and you maintain low complaint rates, ISPs are more likely to accept higher volumes from your IP. Conversely, if engagement is poor or complaints are high, even moderate volumes can trigger deliverability issues, leading to emails going to the spam folder or being rejected entirely.
Understanding these nuances is crucial for optimizing your email program. It's not about pushing the absolute maximum, but about finding the optimal volume that maintains a healthy sender reputation and ensures your emails reach the inbox. This often involves a careful balance between volume increases and reputation, ensuring that your sending practices align with what ISPs expect from reputable senders.
Dedicated versus shared IPs and volume thresholds
For new IP addresses, establishing trust is paramount. ISPs are inherently cautious of new senders to prevent spam. This is why IP warming is a critical process. It involves gradually increasing your email volume over time, allowing ISPs to monitor your sending behavior and build a positive reputation. For instance, Google recommends limiting sending email from a single IP address based on the MX record domain.
Many industry experts suggest a starting volume of a few thousand emails per day for new IPs, slowly escalating over several weeks. A common guideline for maintaining a dedicated IP's reputation is to send at least 100,000 to 250,000 emails per month. Sending significantly less than this can make it difficult for ISPs' algorithms to accurately assess your reputation, potentially leading to inconsistent deliverability. You can learn more about these volume recommendations, including the optimal email volume per IP address and its influencing factors, to optimize your sending strategy.
Dedicated IP
A dedicated IP address is exclusively used by your organization. This gives you full control over your sender reputation, making it ideal for high-volume senders with consistent email campaigns.
Volume: Recommended for senders above 100,000 to 250,000 emails per month, as per various industry guidelines. If you send less than this, it's generally not sufficient to build and maintain a robust reputation with ISPs. More on the minimum and maximum sending volumes for dedicated IPs is available.
Reputation Control: Your sending practices directly impact your IP's reputation, giving you direct control.
Warm-up Required: Essential for new dedicated IPs to gradually build trust with ISPs and avoid initial throttling or blocklisting (or blacklisting).
Shared IP
A shared IP address is used by multiple senders. Your reputation is influenced by the sending practices of others on the same IP pool, which can be a double-edged sword.
Volume: Suitable for senders with lower volumes (e.g., under 100,000 emails per month) or inconsistent sending patterns, where maintaining a dedicated IP reputation would be challenging.
Reputation Control: Less control over your specific IP reputation, as it's shared among others. A bad actor on the same IP can negatively affect your deliverability.
No Warm-up: Typically no warm-up is required, as the ESP manages the overall reputation of the shared pool.
Strategies for high volume sending
When aiming for high email volumes, consistency is crucial. ISPs prefer senders with predictable sending patterns. Sudden, large spikes in volume can appear suspicious, even if your overall reputation is good, and may lead to temporary throttling or even a blocklist (or blacklist) listing. It's better to send a consistent, steady volume than sporadic large bursts, as this helps mailbox providers trust your sending habits over time.
Effective list hygiene is also essential. Sending to unengaged or invalid addresses can quickly degrade your sender reputation, regardless of volume. Regularly cleaning your email lists to remove inactive subscribers, hard bounces, and spam traps is vital. This ensures you're only sending to recipients who genuinely want your emails, which directly contributes to higher engagement and lower complaint rates, allowing for greater email volume without triggering filters.
Inconsistent sending volume warning
Be cautious of inconsistent email sending volumes. ISPs favor predictable patterns. Sending large, infrequent batches can negatively impact your sender reputation, making it harder to reach the inbox. It's better to maintain a steady, gradual increase in volume rather than sudden spikes.
For very large sending volumes, using multiple dedicated IP addresses can be a strategy to distribute traffic and improve throughput. However, this adds complexity as each IP needs its own warming and reputation management. The exact number of IPs needed depends on your total volume and desired sending speed. For example, some sources suggest one dedicated IP per 1 million emails per month, but this is a rough guideline and varies greatly by use case and recipient mix.
Monitoring and maintaining reputation
Continuous monitoring of your email deliverability metrics is non-negotiable for high-volume senders. Pay close attention to your bounce rates, complaint rates, and engagement metrics. Tools like Google Postmaster Tools provide valuable insights into your sender reputation with Google and can help you identify potential issues before they escalate. Consistent monitoring helps you adapt your sending strategy and proactively address any emerging problems.
Furthermore, ensuring your email authentication protocols—SPF, DKIM, and DMARC—are correctly configured and aligned is paramount. These protocols verify your identity as a legitimate sender, which significantly boosts your deliverability and allows ISPs to trust your volume. Proper authentication helps prevent your emails from being flagged as spam or phishing attempts. This is crucial to avoid scenarios like emails going to spam.
ISPs can also implement throttling, temporarily limiting the number of emails they accept from your IP if your sending patterns are suspicious or your reputation is wavering. A robust sending infrastructure should be able to detect these throttling responses and automatically adjust sending speed to avoid further issues, rather than blindly continuing to send emails that will be rejected. This adaptive approach ensures better long-term deliverability.
Views from the trenches
Best practices
Maintain a consistent sending cadence to build a predictable reputation with mailbox providers.
Prioritize list hygiene by regularly removing unengaged subscribers and invalid email addresses.
Implement email authentication (SPF, DKIM, DMARC) to verify your sending identity and build trust.
Actively monitor your deliverability metrics, including bounce and complaint rates, to detect issues early.
Common pitfalls
Sending large, infrequent email bursts that appear suspicious to ISPs and trigger throttling.
Ignoring feedback loops, leading to high complaint rates and damage to sender reputation.
Failing to warm up new dedicated IP addresses, resulting in initial blocklisting.
Sending to outdated or purchased lists that contain spam traps and invalid addresses.
Expert tips
Your actual sending volume is less important than how much your recipients genuinely want your emails.
Adding more IP addresses primarily helps with sending speed to ISPs with per-IP limits.
Configure your MTA to detect and respond to throttling, backing off when necessary, as Microsoft especially rewards this behavior.
There's no single maximum volume recommendation; it varies by use case and recipient demand.
Expert view
Expert from Email Geeks says the maximum volume ISPs will accept varies greatly. For some clients, it's less than 100,000, while for others, it's as high as 20 million. The critical factor is how much recipients want your email.
2019-11-08 - Email Geeks
Marketer view
Marketer from Email Geeks says they often hear about using multiple IPs and rotating them, with some services recommending specific volume ranges for this strategy.
2019-11-09 - Email Geeks
Key takeaways for high-volume email sending
The recommended maximum email volume per IP address isn't a hard limit, but rather a dynamic sweet spot determined by your sending reputation, email quality, and recipient engagement. By focusing on consistent sending, rigorous list hygiene, proper authentication, and continuous monitoring, you can optimize your email program to send high volumes while maintaining excellent deliverability. Always prioritize building and preserving trust with mailbox providers over simply pushing the highest possible volume.
Google and 
Microsoft, evaluate your sending behavior to determine how much email they're willing to accept from your IP address. This behavior includes factors like bounce rates, spam complaint rates, and user engagement (opens and clicks). A strong, positive reputation allows for significantly higher volumes, while a poor one can lead to throttling or blocklisting, even at lower sending rates.
