What is the ideal email volume per IP address per day?

Key findings

• Volume Variability: There is no universally ideal volume; it varies significantly based on sender reputation and other factors.
• Initial Guidance: Some recommendations suggest a starting point of 2-3 million emails per day per IP for flexibility, while others cite 150k-200k messages per day as a good volume for a dedicated IP to maintain reputation. Audience Point indicates about 50,000 messages per day is needed to establish send reputation consistently.
• Provider Specifics: The ideal volume can differ greatly between inbox providers (e.g., Gmail versus Microsoft), necessitating a provider-level assessment.
• Reputation Building: Consistent sending volume is crucial for ISPs to build and maintain a positive sender reputation. Insufficient volume can make it harder for machine learning algorithms to assess IP trustworthiness.

Key considerations

• Sending Patterns: Burst sending (e.g., 2 hours a day) vs. sustained sending (e.g., 10+ hours a day) can impact how much volume an IP can handle.
• Current Performance: If a current volume (e.g., 12 million/day on one IP) is causing deliverability issues or straining, it indicates a need for more IPs or a revised strategy.
• Scalability: When approaching high volumes (e.g., 12 million emails per day), adding more dedicated IPs is a common strategy to distribute the load and maintain performance. This provides wiggle room for growth and peak sending times.
• Platform and Scheduling: The specific email platform used and how emails are scheduled (e.g., bursts, specific timezones) significantly influence the maximum sustainable volume per IP.

Key opinions

• Volume Sensitivity: Marketers frequently question if there is a general threshold for email communications per IP, indicating a common concern about hitting a breaking point.
• Burst vs. Sustained: The nature of sending (short, intense bursts versus consistent, prolonged sending) is seen as a significant factor in an IP's capacity.
• Lower Volume Preference: Many marketers prefer lower daily volumes per IP (e.g., 2-3 million) for increased flexibility and to mitigate issues like per-domain overload.
• High Volume Success: Despite general guidance, some marketers report successfully sending very high volumes, such as 80 million emails per day across just four IPs, though this often requires careful management and additional IPs.

Key considerations

• Benchmarking: If a current volume is working without issues, it can serve as a benchmark for future planning. If it's causing strain, increasing the number of IPs is the likely solution.
• Provider-Level Performance: It is important to assess IP performance at the individual inbox provider level, as sending 1 million emails to Gmail might be very different from sending the same volume to Microsoft.
• Throttling and Peaks: If a single IP struggles to handle peak sending periods (e.g., 5-8 million in an 8-hour window), distributing the load across multiple warmed-up IPs is a practical strategy.
• Hardware vs. IP: Marketers are reminded that IP bandwidth itself isn't the limiting factor; rather, it's the machine's capacity and deliverability issues arising from reputation.

Key opinions

• No Fixed Limit: Experts agree there's no single, ideal volume; it's highly contextual based on sender behavior and recipient engagement.
• Reputation First: The overriding factor is maintaining a strong sender reputation, which can be jeopardized by aggressive sending practices, regardless of the absolute volume.
• Gradual Increase: A cautious, gradual increase in volume (IP warming) is crucial for new IPs or domains to build trust with ISPs.
• ISP Specificity: Different ISPs have different thresholds and algorithms, making a 'one-size-fits-all' approach ineffective. Monitoring ISP-specific metrics is key.

Key considerations

• Engagement Matters: High engagement rates can allow for higher volumes, while poor engagement can quickly lead to throttling or blacklisting.
• Monitor Deliverability: Continuously monitor inbox placement rates, bounces, and complaints. These metrics are better indicators of an IP's health than raw send volume.
• Content Quality: Spammy or irrelevant content can drastically reduce the effective daily volume an IP can send, regardless of its reputation or warm-up status.
• IP Pool Size: For high-volume senders, expanding the IP pool is a standard strategy to distribute risk and maintain deliverability.

Key findings

• Gradual Warm-up: New dedicated IPs require a slow, gradual increase in sending volume over several days or weeks to establish a positive reputation.
• Reputation is Key: Consistent sending volumes are vital for ISPs to build trust and assess sender reputation, making it easier for emails to reach the inbox.
• Volume Ranges for Dedicated IPs: Some documentation suggests dedicated IPs are best for senders with monthly volumes of 100,000 to 200,000 emails or more, as lower volumes make reputation building difficult.
• Scaling IPs: As email volume increases, adding more IP addresses is a common strategy to distribute the load and maintain deliverability. For example, Twilio SendGrid customers can add IPs as their volume grows.

Key considerations

• Consistent Sending: ISPs value a steady and predictable flow of email traffic. Inconsistent or bursty sending can negatively impact reputation and thus the effective daily volume.
• Monitoring is Crucial: Documentation often advises monitoring deliverability metrics (e.g., bounces, complaints, inbox placement) to determine the appropriate pace of volume increase, rather than adhering to rigid numbers.
• ISP-Specific Limits: While not always explicit, documentation implies that different ISPs (e.g., Gmail, Microsoft, Yahoo) may have varying capacities and preferences for incoming mail, which should be learned through observation.
• Sub-optimal Volume: Sending too little email on a dedicated IP can be as detrimental as sending too much, as it makes it difficult for ISPs to gather enough data to properly assess and build the IP's reputation.