Gmail’s Sending Limits

Note: If you want to avoid Gmail’s sending limits, you can use a Delivery Integration, which is available in MergeMail’s Premium and Team plans.

Gmail has published official email sending limits, but in practice its limits and the rules for bounced and rejected emails are very nuanced. We’ll describe what we’ve observed with how Gmail limits, bounces, and rejects emails and describe how to best make sure that your emails are delivered.

Rate Limits

Gmail’s official sending limits are different based on whether you’re using a regular Gmail account (your email address ends in or or a Google Workspace account (your email address ends in anything else). Here are their published limits:

If you have a Google Workspace account, we recommend reading all of the details about limits.

In practice, we’ve observed that Gmail can sometimes limit accounts before they hit these limits. Here are some factors that we’ve seen influence this:

  • The age of the Gmail or Google apps account is (the older, the better)
  • The number of email conversations in the account (the more, the better)
  • Whether the account has sent mass emails before (it’s better if it has)
  • The bounce rate of the account (the lower, the better)
  • The content of the emails (content that is less spammy is better)

What Happens When Gmail Limits Your Emails?

When Gmail limits your outgoing emails, it will typically send you an email notification describing why a specific email either bounced or was rejected. This email notification can take multiple forms:

  • A reply from “Bounce <[email protected]>”
  • “Delivery incomplete: There was a temporary problem delivering your message to …”
    • Typically includes “_is_blocked” at the bottom of the message
  • “Delivery to the following recipient failed permanently”
    • Typically includes “Technical details of permanent failure: Message rejected”
  • Other formats (there are multiple other formats of this notification)

How To Avoid Gmail’s Limits

If you’re using MergeMail, the easiest way to avoid Gmail’s limits is to set up a Delivery Integration, which can be used in the Premium and Team plans. This lets you send email with another email delivery service (instead of using Gmail’s servers), so that Gmail’s limits are no longer an issue.

If you’re sending email using Gmail, then Gmail has a support article about how to fix bounced or rejected emails, but it’s fairly brief. They have some tips in the “Recommendations for sending bulk email” section of this support article. One of the more useful tips is to stagger your emails over two or more days, like sending half of the emails today and half of them tomorrow.

Gmail also has a Sender Guidelines article, which describes a number of best practices. Here’s a list of both those and other useful tips on how to prevent email bounces and rejections:

Lower Your Email Volume

We generally recommend sending relatively small batches initially to make sure that your deliverability is high. Once you’ve earned trust with your recipients and spam filters, you can more confidently increase the volume of your emails.

Include Option To Subscribe

Emailing people who want to read your emails will decrease the chance of Gmail marking your emails as spam. To do this, provide the recipients a way to opt-in to your list (for example, via email or via a checkbox in a form on your website). This is mentioned in the Sender Guidelines article.

Avoid buying lists of emails from a third-party, as these recipients are less likely to want your content.

Include Option To Unsubscribe

Allowing users to unsubscribe will let you target recipients who really want your content, letting you increase your open and click rates. You can let them unsubscribe using a link in your email or by replying to your email with an intent to unsubscribe.

If a user can’t unsubscribe, they are also more likely to mark your email as spam, which can significantly increase Gmail’s likelihood of marking more of your emails as spam.

This is also mentioned in the Sender Guidelines article.

Avoid Emailing Non-existent Email Addresses

If an email address doesn’t exist and you keep trying to email it, this will increase the likelihood that Gmail will classify your emails as spam. In a similar vein, if an email address repeatedly returns bounces, you should stop emailing that address.

Prevent Spam Reports

The more recipients who mark your emails as spam, the more likely it is that more of your emails will be marked as spam. To avoid this, make sure that your emails provide value to your recipients and aren’t unwanted.

Avoid Using Third-Party Email Templates

If you’re using publicly-available email templates (especially if your content is not unique), it’s fairly common that spam filters will mark your emails as being spam.