Summary
The optimal email sending speed to avoid spam folders is heavily dependent on sender reputation and recipient engagement. A consistent theme across expert and documentation sources is the importance of a gradual IP warm-up process, starting with low volumes and increasing them over time. After building a positive reputation, the sending rate becomes less critical, and recipient engagement takes precedence. Monitoring sender reputation, engagement metrics (bounce rates, spam complaints, deferrals), and adhering to email provider-specific sending limits are crucial. Negative tactics, such as removing list-unsubscribe headers, should be avoided. New IPs need a careful and deliberate warm-up process to build a positive reputation.
Key findings
- IP Warm-up is Key: A gradual IP warm-up with low initial volumes is essential for new IPs and domains.
- Reputation Matters Most: Sender reputation is a primary factor in email deliverability, impacting inbox placement.
- Engagement is Crucial: Recipient engagement significantly affects deliverability once a positive reputation is established.
- Monitor Metrics: Tracking sender reputation, bounce rates, spam complaints, and deferrals is vital.
- Avoid Negative Practices: Practices that try to trick ISPs or recipients will negatively impact deliverability.
- Provider Limits: Staying aware of and following email provider-specific sending limits is important.
Key considerations
- Consistent Sending: Maintaining consistent sending habits helps build trust with ISPs.
- Feedback Loops: Actively monitor and address feedback from ISPs (e.g., deferrals, bounce rates).
- Ethical Sending: Focus on ethical sending practices to maintain a positive sender reputation.
- Content Quality: Deliver content that recipients want to receive to boost engagement and avoid spam filters.
- Adjust to Scale: Adapt sending practices and volume when scaling up email campaigns.
What email marketers say
7 marketer opinions
The optimal email sending speed to avoid spam folders and maintain a good reputation involves a gradual increase in sending volume, especially when warming up a new IP address or domain. Monitoring sender reputation and engagement metrics is crucial, and adjustments to sending speed should be made based on feedback from ISPs and performance data. Utilizing a dedicated IP address and warming it up carefully is also key. Consideration should be given to email provider specific sending limits.
Key opinions
- Gradual Increase: Start with low sending volumes and gradually increase over time, especially during IP or domain warm-up.
- Reputation Monitoring: Continuously monitor your sender reputation and make adjustments to sending practices based on performance.
- Engagement Metrics: Pay close attention to engagement metrics such as bounce rates, spam complaints, and positive interactions.
- Dedicated IP: Using a dedicated IP address and warming it up carefully is essential for controlling sender reputation and deliverability.
- Provider Limits: Consider email provider-specific sending limits when planning your sending volume.
Key considerations
- IP Warm-up: Warming up a new IP address is critical for establishing a positive sending reputation.
- ISP Feedback: Pay attention to feedback from ISPs and adjust sending speed accordingly.
- Consistent Habits: Maintain consistent sending habits to build trust with ISPs and email recipients.
- Scaling Campaigns: Adjust sending practices and volume when scaling up email campaigns.
- Positive Engagement: Encourage and maintain positive engagement with your emails to improve sender reputation.
Marketer view
Email marketer from Email Marketing Forum MailKing responds that using a dedicated IP address and carefully warming it up is essential for controlling sender reputation and deliverability. Start with small volumes and gradually increase based on engagement metrics.
10 Apr 2025 - Email Marketing Forum
Marketer view
Email marketer from Email on Acid shares that sending reputation is a key factor in deliverability. They advise monitoring your reputation and adjusting sending practices accordingly, especially when scaling up your email campaigns.
27 Jan 2023 - Email on Acid
What the experts say
7 expert opinions
The best email sending speed depends heavily on sender reputation. Initially, a slow, gradual warm-up is crucial for building a positive reputation with ISPs. Once established, the sending rate is less critical, with recipient engagement becoming the dominant factor. However, it's essential to monitor deferrals and avoid practices like removing list-unsubscribe headers to manipulate filters. A conservative approach to IP warm-up, with gradual volume increases based on positive engagement, is generally recommended. The Gmail promotions folder is separate from spam and is more about content and reputation, not sending speed.
Key opinions
- Initial Sending Speed: Slower sending speed is critical when initially building a reputation with ISPs (IP Warm-up).
- Engagement-Driven Sending: After establishing a positive reputation, sending rate is dominated by how much recipients want to receive the mail.
- No Magic Number: There's no fixed 'best' sending speed; high volumes are fine if recipients engage, but detrimental otherwise.
- Promotions Folder: Placement in Gmail's promotions folder depends on content and reputation, not directly on sending speed.
- Avoid Negative Tactics: Do not try to manipulate filters by removing list-unsubscribe headers or mimicking personal emails.
- Watch Deferrals: Increasing deferrals are an indication of pushing your luck with an ISP.
Key considerations
- IP Warm-up: Carefully and deliberately warm up new IPs with gradually increasing volumes.
- Recipient Engagement: Focus on delivering content recipients want, as engagement is a major factor in deliverability.
- Conservative Approach: A conservative and documented IP warm-up approach can be a good starting point.
- Monitor Soft Bounces: Monitor deferrals as a signal to slow down your sending speed.
- Ethical Practices: Avoid tactics that are designed to trick or deceive recipients as this degrades your sending reputation.
Expert view
Expert from Spam Resource explains that IP warm-up involves gradually increasing sending volume and monitoring sender reputation. They advise starting with a small number of emails to engaged recipients and gradually increasing volume based on positive engagement.
3 Jul 2023 - Spam Resource
Expert view
Expert from Email Geeks states that removing list-unsubscribe headers as a hack to try and avoid an ISPs mail filters is a bad thing, and would correlate with other bad behavior. He adds that sending bulk mail that does its best to look like personal 1:1 email, to avoid spam filters and deceive the recipient … not so much.
26 Feb 2023 - Email Geeks
What the documentation says
3 technical articles
Email deliverability documentation emphasizes that consistently sending email helps build a positive sender reputation. A key recommendation across sources is to gradually increase sending volumes to avoid being flagged as spam, especially when establishing a new sending domain. Careful management of sending volume and close attention to feedback loops are critical for maintaining deliverability.
Key findings
- Consistent Sending: Consistently sending email builds a positive sender reputation.
- Gradual Volume Increase: Gradually increase sending volumes to avoid spam flags.
- New Domain Caution: Careful volume management is especially important when establishing a new sending domain.
- Feedback Loops: Pay close attention to feedback loops (e.g., bounce rates, spam complaints) to monitor deliverability.
Key considerations
- Sender Reputation: Prioritize building and maintaining a positive sender reputation.
- Best Practices: Adhere to email sending best practices to avoid being flagged as spam.
- Volume Management: Actively manage and control your email sending volume.
- Deliverability Monitoring: Continuously monitor email deliverability metrics to identify and address any issues.
Technical article
Documentation from Google Postmaster Tools explains that consistently sending email helps build a positive reputation. They advise gradually increasing sending volume to avoid being marked as spam.
28 Jul 2021 - Google
Technical article
Documentation from RFC explains that standards documents around email sending recommend careful management of sending volume, particularly when establishing a new sending domain, and careful attention to feedback loops to monitor deliverability.
21 Mar 2023 - RFC
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