How many emails can I send per second per IP to Gmail, Yahoo and O365?
Summary
What email marketers say11Marketer opinions
Email marketer from SuperOffice advises focusing on quality over quantity when it comes to email deliverability. Send relevant emails to people who want them. Don't send high volume emails. Instead personalize each one.
Email marketer from Litmus recommends monitoring your sender reputation using tools like Google Postmaster Tools and Microsoft SNDS to identify and address deliverability issues proactively. These tools provide insights into your sending reputation and potential problems.
Email marketer from HubSpot highlights that focusing on engagement metrics (opens, clicks) and maintaining a clean email list are more important than specific sending rates. High engagement signals to ISPs that your emails are wanted.
Email marketer from Mailjet advises to monitor bounce rates and engagement metrics closely when increasing sending volume. High bounce rates or low engagement can trigger spam filters, regardless of the sending rate.
Email marketer from Neil Patel Digital explains that while there's no hard and fast rule, you should start slow and gradually increase volume. Gmail, Yahoo, and O365 all monitor sending patterns and sudden spikes can negatively impact your sender reputation.
Email marketer from Email Geeks shares that technically there isn't a limit and he has seen millions of emails sent per day per IP without issues, even with spikes on big mailing days.
Email marketer from ActiveCampaign highlights that exceeding a threshold of 5,000 emails to Gmail within a short timeframe without proper authentication and engagement can trigger deliverability issues.
Email marketer from SendGrid explains the importance of IP warming, advising a gradual ramp-up of email volume to build a positive sender reputation with ISPs like Gmail, Yahoo, and Microsoft. Starting with a few hundred emails per day and gradually increasing is recommended.
Email marketer from Reddit User u/EmailGuru shares that most major email providers do not publish specific sending rates, but instead use algorithms to determine acceptable volumes based on sender reputation, authentication, and engagement.
Email marketer from Email on Acid explains that sender reputation, list hygiene, and content quality are all critical factors affecting deliverability, in addition to sending volume. Poor practices in any of these areas can negatively impact your sending reputation.
Email marketer from Campaign Monitor shares that throttling limits are closely guarded and vary based on sender reputation, advising consistent, authenticated sending with engaged subscribers.
What the experts say7Expert opinions
Expert from Word to the Wise explains that throttling limits will vary for each sender, and depends on your individual reputation. A strong reputation allows for higher sending volumes.
Email marketer from Email Geeks recalls Craig Spiezle mentioning a maximum of 4 million emails per day per IP at Hotmail with perfect reputation and recommends 1 million per IP per day.
Expert from Spam Resource explains that the number of IPs you use is secondary to properly warming those IPs. The key is consistent and slowly increasing volume, irrespective of the exact number of IPs.
Expert from Email Geeks explains that throttling is typically reputation-driven, making it difficult to provide a universal answer regarding emails delivered per second per IP.
Expert from Email Geeks clarifies that 4 million was for Hotmail MXen, and total daily traffic could be much higher.
Expert from Email Geeks explains that suitable hardware is required to send emails quickly. He advises sticking to around 2 million emails per IP per day to avoid pain, although more is possible.
Expert from Email Geeks shares experience with a client consistently sending 20 million emails per day per IP.
What the documentation says4Technical articles
Documentation from SparkPost states while specific rates depend on reputation, they provide tools to monitor and optimize throttle rates for each ISP to ensure optimal delivery without triggering spam filters.
Documentation from Microsoft Learn details sending limits in Exchange Online, which depend on the user's license and the recipient's domain. These limits are enforced to prevent abuse and maintain service quality.
Documentation from Yahoo Help emphasizes the importance of email authentication (SPF, DKIM, DMARC) for improving deliverability and avoiding spam filters, regardless of sending volume.
Documentation from Google Workspace Admin Help states that Gmail has sending limits to prevent spam and maintain system stability. These limits depend on the type of account (e.g., free Gmail vs. Google Workspace) and can be found in their documentation.