Summary
The recommended initial email sending volumes for deliverability are not universally fixed and depend heavily on several factors, including the age and reputation of your domain, whether you are using a new or warmed IP address, and the specific mailbox provider you are sending to. While some older guidelines or large ESPs might suggest starting with thousands of emails, modern best practices, especially for new sending infrastructures or domains, advocate for a much more gradual ramp-up, often starting with as few as 10-50 emails per day to specific ISPs like Gmail. The goal is to build a positive sender reputation steadily, rather than triggering spam filters with sudden, large volumes. Consistent monitoring of your sender reputation and engagement metrics is crucial during this phase.
Key findings
- Varied advice: There is no single consensus on initial sending volumes, with recommendations ranging from 10-20 to 5,000 emails per day.
- ISP specificity: Major mailbox providers like Gmail often advise very low starting volumes, sometimes in the single digits for new senders on day one.
- Gradual ramp-up: A slow, consistent increase in volume is generally more effective for building positive reputation than rapid escalation.
- Context matters: Initial volumes depend on whether it's a new domain, a subdomain, or an existing domain migrating to a new vendor.
Key considerations
- Domain reputation: A brand new domain will require a much more cautious warm-up than an established one, even if migrating IPs. For more information, read about why emails from new domains go to spam.
- Engagement focus: Prioritize sending to highly engaged subscribers during the initial warming phase to demonstrate positive sending behavior.
- Monitoring: Closely monitor deliverability metrics, including open rates, bounce rates, and spam complaints, to adjust your sending volume.
- Patience: Warming an IP or domain takes time. Rushing the process can lead to long-term deliverability issues and being added to a blacklist (or blocklist).
What email marketers say
Email marketers often face a balancing act when it comes to initial sending volumes. On one hand, there's the desire to reach their audience as quickly as possible. On the other hand, they must adhere to best practices for building a strong sender reputation, which typically involves a conservative, gradual increase in email volume. Many marketers prioritize starting small, sometimes as low as 10-20 emails, to major ISPs, while acknowledging the challenge of convincing clients to adopt such a slow approach. They recognize that rushing the process, even with a seemingly established domain, can negatively impact inbox placement and overall email deliverability.
Key opinions
- Slow and steady: Many marketers advocate for starting with a very low volume, like 10-20 emails, especially for warming up new IPs or domains.
- Client pushback: It can be difficult to persuade clients to adopt a slow warm-up strategy, as they often want to send emails quickly.
- ISP variations: Some marketers start with a slightly higher volume to Gmail (e.g., 50 per day) but control the hourly sending rate to avoid issues.
- Impact on open rates: Sending too many emails too quickly, particularly at the start, can lead to a noticeable drop in open rates, indicating poor inbox placement.
Key considerations
- Domain type: The approach to initial volume should differ based on whether it's a completely new domain, a subdomain of an existing one, or simply a new sending vendor for an established domain. For details on why, review how email reputation transfers.
- Reputation building: The primary goal of initial low volumes is to build a positive sending reputation with mailbox providers, demonstrating consistent and desired sending patterns.
- Engagement is key: Even with low volumes, ensuring high engagement from initial recipients is crucial. This reinforces positive signals to ISPs. This is particularly important when considering how to improve email inbox placement.
- Avoid surprises: Sudden spikes in volume can look like spamming behavior to ISPs, regardless of content quality.
Email marketer from Email Geeks notes that they have never seen an Email Service Provider (ESP) recommend starting with a low volume like 10-20 emails, indicating a potential disconnect between general industry advice and specific ESP guidelines.
An email marketer from Email Geeks states they can name at least three ESPs that recommend such low starting volumes, implying that while less common, some providers do indeed advocate for very conservative warm-up strategies.
What the experts say
Email deliverability experts consistently emphasize that successful warm-up is not about hitting arbitrary volume numbers quickly, but rather about establishing a positive sender reputation through consistent and engaged sending behavior. They often highlight the discrepancies between published ESP recommendations and the realities observed in real-world deliverability challenges. Experts caution against overly aggressive initial sending volumes, particularly to major ISPs like Gmail, which are known to be highly sensitive to sudden spikes in volume from unestablished IPs or domains. The consensus points towards a methodical, gradual approach, prioritizing engagement over raw numbers to avoid blocklisting and ensure long-term inbox placement.
Key opinions
- Gmail's sensitivity: Experts indicate that Gmail has historically recommended very low initial sending volumes, sometimes as low as single digits on day one.
- Discrepancy in advice: There can be a notable difference between publicly stated policies from ESPs and the practical advice given by their deliverability teams.
- Reputation over volume: The overarching goal is to establish a good sender reputation, which is achieved through consistent, positive sending patterns, not just high volume.
- Holistic view: The type of domain (new, subdomain, existing) and prior sending history significantly influence the appropriate warm-up strategy and initial volumes. Learn more about IP reputation in business partnerships.
Key considerations
- Engagement as a signal: High engagement (opens, clicks) on initial sends is a strong positive signal to ISPs, helping to build trust and allow for increased volumes.
- ISP-specific warming: It is often beneficial to warm up IPs or domains by individual ISP, focusing on major providers like Gmail, Outlook, and Yahoo with tailored volume increases. Read about strategies for warming by individual ISP.
- Risk of blocklisting: Aggressive initial sending volumes significantly increase the risk of being placed on a blocklist or blacklist, severely impeding future deliverability.
- Monitoring tools: Utilizing tools to monitor deliverability, spam complaints, and blacklists is crucial during the warm-up period to quickly identify and address any issues. Understanding email deliverability rates is essential.
Deliverability expert from Email Geeks indicates that despite some ESPs' official documentation, what happens in the trenches of deliverability can be quite different, suggesting that practical, hands-on experience often dictates a more nuanced approach than published guides.
Email deliverability expert from Email Geeks asks for clarification on whether the 5,000 email starting volume for IBM was specifically to Gmail on day one, indicating that initial volumes vary significantly based on the recipient ISP and the specific stage of warm-up.
What the documentation says
Official documentation from various Email Service Providers (ESPs) and mailbox providers often provides general guidelines for IP warming and initial sending volumes. While these documents aim to offer a structured approach, they sometimes present higher initial volumes than what is practically advised by deliverability teams working directly with mailbox providers. The core principle across most documentation is the importance of a gradual ramp-up, with a strong emphasis on consistent sending and positive engagement signals. Documentation typically highlights that mailbox providers monitor sending patterns and reputation scores closely, making sudden, uncharacteristic spikes in volume detrimental to inbox placement and the ability to avoid being added to a blacklist.
Key findings
- ESP warm-up schedules: Many ESPs, like Salesforce, provide structured IP address warming schedules that begin with a certain number of sends and gradually increase over time.
- Reputation building: Documentation consistently states that warming is essential for building a positive sending reputation with various mailbox providers.
- Engagement driven: The success of warm-up depends on sending to engaged recipients to generate positive interactions (opens, clicks) rather than spam complaints.
- Daily increases: Typical warm-up guides involve incremental daily increases in sending volume, rather than large jumps.
Key considerations
- Patience and consistency: Documentation stresses that IP warming is a long-term process, requiring consistent sending patterns and patience to see results.
- Monitoring required: Regular monitoring of deliverability metrics (bounce rates, spam complaints, opens) is crucial to adjust the sending schedule as needed. Read about the 2025 Email Deliverability Report.
- ISP-specific variations: While general guidelines exist, documentation often hints that specific mailbox providers may have unique requirements or respond differently to warm-up efforts.
- Audience quality: Clean and engaged lists are paramount for successful warming. Sending to inactive or low-quality contacts can hinder reputation building from the start. This ties into how email list quality impacts deliverability.
Salesforce documentation on IP warming outlines a typical schedule that recommends starting with a baseline volume and gradually increasing it daily, emphasizing consistency and positive engagement to build sender reputation effectively over time.
Mailgun's deliverability guide states that IP warming is a critical process for new IPs to establish trust with mailbox providers, advising a methodical ramp-up of sending volume to avoid being flagged as spam.
![Email Deliverability: 12 Best Practices for Marketers [2023]](https://tinuiti.com/wp-content/uploads/2023/12/Screenshot-2023-07-17-124523.jpg)
.png)
![Email Deliverability: Avoiding The Spam Folder [2025]](https://moosend.com/wp-content/uploads/2022/09/Email-Deliverability.png)
