Should I manually throttle my email sends when using a shared IP for large campaigns?

Manual throttling (sending in small hourly batches) is generally not necessary on an active shared IP. Your ESP's infrastructure typically handles optimal sending rates. Focus more on the quality of your recipient list and the relevance of your content.

Does my sender reputation still matter if I'm on a shared IP?

Yes, sender reputation is crucial regardless of IP type. Even on a shared IP, your domain's sending behavior (engagement, complaints, bounces) heavily influences your deliverability. A poor domain reputation can lead to emails landing in spam, even if the shared IP is generally healthy. This is why you should know how to fix email deliverability issues .

When should I consider switching from a shared IP to a dedicated IP?

Consider a dedicated IP if you consistently send large volumes (e.g., over 100,000-250,000 emails per month) and have highly consistent sending patterns. It gives you more control over your reputation. For lower, irregular, or fluctuating volumes, shared IPs are typically more suitable.

Can other senders on a shared IP affect my email deliverability?

Poor sending practices by other users on your shared IP can negatively impact your deliverability. This is why choosing a reputable ESP that actively monitors and manages its shared IP pools is very important. Regularly monitoring for blocklist (or blacklist) listings can also provide early warnings.

When using a shared IP, how should I manage sending volume for larger email campaigns? - Sender reputation - Email deliverability - Knowledge base

Q: Do I need to warm up a shared IP before sending a large email campaign?

For most active shared IPs, your ESP already manages a large, consistent volume, meaning your individual campaigns, even large ones, don't typically require a specific warm-up. The IP has established a reputation. However, always prioritize good list hygiene and sender practices to protect your domain reputation.

When using a shared IP for email campaigns, a common question arises regarding how to manage sending volume, particularly for larger deployments. Many email senders operate with shared IP addresses, benefiting from the pooled reputation and reduced overhead. However, the dynamics of shared IPs mean your sending behavior is intertwined with others, leading to specific considerations for volume management.

The perception that every large campaign on a shared IP requires a full IP warming process is a frequent misconception. While IP warming is crucial for dedicated IPs, the approach differs significantly when you are part of a shared pool. Your primary concern shifts from building initial IP trust to maintaining a positive sender reputation within the shared environment.

Understanding shared IP dynamics

Understanding how shared IP addresses function is fundamental to effective volume management. A shared IP address is utilized by multiple senders, with your email service provider (ESP) typically managing the overall IP reputation. This setup means your individual sending volume is often a small fraction of the total traffic originating from that IP pool, which can be an advantage for smaller or fluctuating senders.

For established shared IPs, the cumulative volume sent by all users often provides enough consistent traffic that your individual campaigns, even larger ones, don't typically require a specific warm-up. The IP has already built a reputation with internet service providers (ISPs). This allows for greater flexibility for senders with variable or seasonal volumes, as they can send emails without needing to re-warm the IP for each surge.

Shared IP addresses

Reputation: Reputation is shared among many senders, managed by the ESP.
Warm-up: Generally pre-warmed, suitable for immediate sending without extensive ramp-up.
Volume: Ideal for low-to-medium volume, or fluctuating sending patterns.
Control: Less direct control over IP reputation, relying on the ESP's overall management.

Dedicated IP addresses

Reputation: Your sending practices solely determine the IP's reputation.
Warm-up: Requires a gradual volume ramp-up (IP warming) to build trust.
Volume: Best for high, consistent sending volumes to maintain reputation.
Control: Full control over your sending reputation and deliverability.

Managing volume spikes on shared IPs

For most senders on a shared IP, especially those with established sending patterns, sudden spikes in volume for a large campaign (like a 30,000-email newsletter) don't typically necessitate a specific pre-warming strategy for the IP itself. The ESP is managing a collective reputation for a much larger volume than your individual contribution. What matters more is your domain's historical sending behavior and recipient engagement.

While manual throttling (sending a few thousand per hour) isn't usually required for active shared IPs, for extremely large or unprecedented campaign volumes, it can still be beneficial to send in batches. This isn't about IP warming as much as it is about smoothing out the engagement response and minimizing potential impact if there are issues with the list quality for that particular campaign. ISPs, like Google, advise against sudden, significant spikes from new or inconsistent senders.

The key is to understand that the shared IP itself is likely already warmed and carrying a consistent baseline volume. Your focus should remain on maintaining a healthy sender reputation, regardless of the IP type, by ensuring high-quality recipient lists and engaging content. This helps your domain's reputation, which is increasingly important to ISPs, even on shared IPs.

Monitoring and maintaining your sender reputation

While shared IPs can absorb volume fluctuations, the overall reputation of that shared IP pool remains critical. If other senders on your shared IP engage in poor sending practices, it can negatively affect your deliverability. This is why it's vital to choose a reputable ESP that actively manages its shared IP pools and removes problematic senders. Even if your sending is stellar, a poor shared IP reputation can lead to emails landing in spam or being blocked.

Continuously monitoring your email program's performance is essential. Pay close attention to engagement metrics (opens, clicks), bounce rates, and spam complaint rates. High complaint rates, even for a single campaign, can harm your domain's reputation and potentially lead to your ESP moving you to a different shared IP, or even a dedicated one, if your volume justifies it.

Regularly check IP and domain blacklists (or blocklists) to ensure your shared IP isn't listed due to the actions of others. While your ESP should handle this, proactive monitoring can give you an early warning. If a shared IP does get listed on a blocklist, your emails may experience significant deliverability issues, impacting your campaigns regardless of volume.

Key factors for deliverability on shared IPs

Maintaining strong sender reputation and list hygiene is paramount when operating on shared IP addresses. While shared IPs offer flexibility, your sending practices still directly influence your domain's standing with ISPs. Poor engagement or high spam complaints from your campaigns can harm your individual domain's reputation, even if the shared IP itself has a decent overall score. This can lead to your emails being filtered to spam folders, regardless of the IP's overall health.

When a dedicated IP might be necessary

There comes a point where your email sending volume, consistency, and unique needs might suggest moving from a shared IP to a dedicated IP address. Generally, if you're consistently sending hundreds of thousands to millions of emails per month, a dedicated IP provides more control over your sender reputation.

The threshold for considering a dedicated IP varies by ESP, but a common guideline is if you send over 100,000 to 250,000 emails per month consistently. Below these volumes, or with highly inconsistent sending, a shared IP is often more suitable because the collective volume helps smooth out fluctuations and absorb individual sender impact.

If you do decide to switch to a dedicated IP, remember that it requires a proper IP warming process to build its reputation from scratch. This involves gradually increasing your sending volume over several weeks. It's a significant undertaking that requires careful planning and consistent sending to be effective.

Shared IP best practices for consistent volume

In the scenario of sending 2,000 daily automation emails and a monthly 30,000 newsletter on a shared IP, specific volume management strategies for shared IPs are generally straightforward. For most active shared IPs, your 30K monthly newsletter is a relatively small volume and won't require a dedicated IP warming procedure each month. The shared IP environment is designed to absorb such fluctuations within its larger sending capacity. However, if this is the first time your domain is sending to such a large audience, a gradual ramp-up could help establish that history for your specific domain reputation.

When sending the 30K newsletter over multiple days, for example, 10K per day, you generally don't need to manually throttle each 10K send down to a few thousand per hour. On an active, well-managed shared IP, the volume is typically sufficient for your sends to blend into the overall traffic. The ESP's systems are designed to manage the sending rates to various ISPs automatically.

Views from the trenches

Best practices

Maintain consistent engagement to build your domain's positive sending reputation.

Segment your audience and send relevant content to improve engagement metrics.

Clean your email lists regularly to remove inactive subscribers and spam traps.

Common pitfalls

Ignoring domain reputation while relying solely on shared IP reputation.

Sending to unengaged or old lists, which increases bounces and complaints.

Failing to monitor your domain and IP for blocklist (blacklist) listings.

Expert tips

For very large or new audiences, a gentle ramp-up can still benefit domain history.

Consider batching large, non-time-sensitive campaigns for engagement smoothing.

Always prioritize list hygiene and content quality over volume throttling on shared IPs.

Expert view

Expert from Email Geeks says that if your volumes are within typical shared IP ranges, you will likely disappear into the noise of volume changes, so a significant ramp-up for each large campaign is not generally a big deal. However, if your domain has no history of sending to a new large segment, gradually increasing volume can help establish that history for the domain.

2022-08-19 - Email Geeks

Expert view

Expert from Email Geeks says that you shouldn't need to manually throttle sends (e.g., a few thousand per hour) from an active shared IP because the ESP's infrastructure is designed to handle this.

2022-08-19 - Email Geeks

Key takeaways for shared IP volume management

Managing sending volume for larger email campaigns on a shared IP largely comes down to trusting your ESP's shared IP management and focusing on your own sender practices. For established domains, most large campaigns won't require specific IP warm-ups on a shared IP because the collective volume handled by the ESP is already maintaining the IP's reputation.

Prioritize maintaining a clean list, fostering high engagement, and monitoring your domain's reputation. If your sending volume grows consistently to very high levels (e.g., hundreds of thousands to millions per month), then it may be time to consider transitioning to a dedicated IP for more granular control over your deliverability.