Summary
Batching email sends for deliverability is a complex issue with varying perspectives. Generally, sending emails in large batches is not recommended, particularly for healthy email marketing programs or new IPs/domains, as it can trigger spam filters and overwhelm recipient servers. Experts emphasize the importance of gradual ramp-up, consistent sending rates, and IP warming to establish trust with ISPs. Segmentation, list cleaning, and strategic scheduling are crucial for optimal deliverability. Batching can be a beneficial strategy for specific scenarios such as managing high website traffic or handling time-sensitive sends. However, maintaining a good sender reputation is paramount and often outweighs the benefits of batching alone.
Key findings
- Gradual Ramp-Up: Gradually increasing sending volume, especially for new IPs/domains, is crucial for building a positive sender reputation.
- Consistent Sending: Maintaining consistent sending rates helps avoid triggering spam filters.
- Segmentation: Segmenting email lists and sending personalized messages to smaller groups improves engagement and deliverability.
- Sender Reputation: A strong sender reputation is paramount and often outweighs the benefits of batching.
- IP Warming: IP warming is essential for new IPs to establish trust with ISPs and prevent being flagged as spam.
- Limited Use Cases: Batching may be beneficial in specific scenarios like managing high traffic or handling time-sensitive sends.
- Throttling Impact: Proper throttling is crucial to managing sending reputation and avoiding ISP blocks.
Key considerations
- New IP/Domain Strategy: Develop a robust IP warming strategy when starting with a new IP address or domain.
- Segmentation Tactics: Implement effective segmentation strategies to target specific audiences with relevant content.
- Consistent Schedule: Establish a consistent sending schedule to avoid sudden volume spikes.
- Clean Email Lists: Regularly clean email lists to remove inactive or invalid addresses and maintain a good sender reputation.
- Traffic Management: Consider batching emails when expecting high website traffic or call center volume to manage resources.
- Throttling Balance: Balance throttling strategies to avoid being too aggressive and wasting resources.
- Monitor Deliverability: Continuously monitor deliverability metrics and make adjustments to sending practices.
What email marketers say
12 marketer opinions
Batching email sends for deliverability is a nuanced issue. While it was crucial in the past to avoid overloading shared IPs, its relevance has shifted with the prevalence of dedicated IPs and the importance of sender reputation. Batching can be beneficial for very large sends, new IPs requiring gradual warm-up, or when anticipating high website traffic. However, sending large, unsegmented campaigns is generally discouraged. Gradual sending, segmentation, list cleaning, and strategic scheduling are recommended for optimal deliverability.
Key opinions
- Segmentation: Segmentation is crucial to prevent deliverability issues by sending personalized messages to smaller groups instead of bulk emails to everyone.
- Sender Reputation: Building and maintaining a positive sender reputation is more important than batching alone. A good sender reputation allows for sending larger volumes without issues.
- Volume Control: Gradually increasing sending volume is essential, especially with new IPs, to avoid triggering spam filters. Avoid sending email in bursts.
- IP Warming: Warming up a new IP address gradually by increasing email volume helps establish trust with mailbox providers and prevents emails from going to spam.
- Specific Circumstances: Batching may be beneficial for time-sensitive, large sends, or when expecting high website/call center traffic.
- Staggered Sending: Staggering sends is recommended to mimic human sending behavior which avoids triggering spam filters.
Key considerations
- List Hygiene: Maintain a clean email list to improve sender reputation and avoid sending to inactive or invalid email addresses.
- Gradual Increase: If sending from a new IP or domain, gradually increase sending volume to establish trust with ISPs.
- Segmentation Strategy: Develop a robust segmentation strategy to target specific audiences with relevant content.
- Email Scheduling: Schedule emails strategically to avoid sending all messages at once, thereby preventing server overload and reducing the risk of being flagged as spam.
- Website Traffic: Consider batching emails if anticipating a high flow of customers to your website or call center to manage resources.
- Call Centre: Consider batching emails if you need to manage volume of customer support requests.
Marketer view
Email marketer from Email Geeks explains batching emails if expecting a high flow of customers to your website/call centre to better manage inbound calls.
15 Jun 2023 - Email Geeks
Marketer view
Email marketer from Mailchimp explains that they don't recommend sending large campaigns to your entire list at once. Consider segmenting your list and sending to smaller groups. This helps monitor engagement and address any deliverability issues proactively.
25 Nov 2022 - Mailchimp
What the experts say
4 expert opinions
The experts agree that batching is generally not recommended for healthy email programs. However, batching can be a solution for specific problems. Email volume and sender reputation are important factors, and corporate filters are unlikely to be affected by low volume. Throttling helps manage sending reputation. Proper IP address warm up can prevent being blocked.
Key opinions
- Healthy Programs: Batching is not generally recommended for healthy email marketing programs.
- Volume Matters: Sending 20M emails a year (roughly 42,000 an hour) is a relatively small amount and doesn't typically require batching.
- Corporate Filters: Corporate email filters are unlikely to be significantly impacted by low sending volumes.
- Sender Reputation: Good sender reputation is key, and gradual volume increases are important for new IPs/domains.
- Throttling: Throttling controls email sending rates to manage sender reputation and avoid blocks.
Key considerations
- Specific Problems: Consider batching as a remedy for specific deliverability problems, not as a default practice.
- Throttling Strategy: Implement throttling carefully to balance deliverability with efficient resource use.
- IP/Domain Warmup: Gradually increase sending volume from new IPs or domains to build sender reputation.
- Acceptable Volume: Understand acceptable email volume in your specific context to avoid triggering spam filters.
- Traffic Spikes: Consider batching to mitigate issues related to website traffic spikes.
Expert view
Expert from Email Geeks explains that batching is not recommended for healthy marketing programs but can be part of a remedy if addressing a specific problem. They also highlight that sending 20M emails a year translates to roughly 42,000 an hour, which is a small amount and doesn't necessitate batching. They confirm that corporate filters are unlikely to be affected by this volume.
25 Feb 2023 - Email Geeks
Expert view
Expert from Word to the Wise explains throttling is used to control the number of connections, messages per connection, and recipients per message over a specific time. Proper throttling can help manage your sending reputation and avoid being blocked by ISPs, but too aggressive throttling can waste resources.
10 Feb 2024 - Word to the Wise
What the documentation says
4 technical articles
Email deliverability, according to documentation from Google, Microsoft, the RFC, and SparkPost, benefits from consistent sending IP addresses, gradual volume increases, and stable sending rates. Sudden email bursts and spikes in volume can trigger spam filters, potentially overwhelming systems and hurting sender reputation. IP warming is crucial for new IPs to establish trust with ISPs.
Key findings
- Consistent IP: Using a consistent sending IP address is vital for identification and deliverability.
- Gradual Volume: Gradually increasing sending volume is crucial for establishing sender reputation and avoiding spam filters.
- Stable Rates: Maintaining consistent sending rates helps prevent triggering spam filters.
- Avoid Bursts: Avoid sending email bursts, as sudden spikes can lead to deliverability issues.
- IP Warming: Warming up IP address helps establish trust and prevent being flagged as spam.
- Rate Limiting: MTA rate limiting avoids being overwhelmed by email bursts.
Key considerations
- Ramping Strategy: Develop a clear strategy for gradually increasing email volume, especially for new IPs.
- Consistent Schedule: Establish and maintain a consistent sending schedule to avoid sudden spikes.
- Infrastructure Capacity: Ensure your infrastructure can handle the planned email volume and avoid overwhelming systems.
- Monitoring: Monitor deliverability metrics and make adjustments as needed to optimize sending practices.
- IP Address: Prioritise using a consistent IP address
Technical article
Documentation from Microsoft explains that sudden spikes in email volume can trigger spam filters. They recommend gradually increasing sending volume and maintaining a consistent sending schedule.
23 Sep 2024 - Microsoft
Technical article
Documentation from RFC states that a message transfer agent (MTA) can implement rate limiting to prevent being overwhelmed by sudden bursts of messages from a single source. This is often a measure to protect against denial-of-service attacks or spam.
9 Jun 2024 - RFC-Editor
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