What is the sendmail / email sending limit?

The sendmail limit caps how many emails your website can send per hour using PHP's mail() function. Most shared hosts allow 150–500 emails/hour. Exceeding it silently drops emails — password resets, order confirmations, and contact forms stop arriving with no error shown to the user.

Imagine you're throwing a party, and you want to invite all your friends. However, your parents say you can only send out a certain number of invitations per hour. This is similar to the sendmail or email sending limit on a web hosting account. It's a rule that limits how many emails your website can send in a given hour. If you're using PHP's mail() function to send emails like password resets or order confirmations, this limit is crucial. Most shared hosting plans cap this at around 150 to 500 emails per hour. If you go over this limit, some of your emails might just disappear without any warning.

Technically speaking, the sendmail limit is a server-side restriction set by your hosting provider. When your website uses PHP's mail() function, it communicates with the server's mail transfer agent (MTA), such as Sendmail or Postfix, to send out emails. The hosting provider configures the server to track how many emails are sent from your account. If the number exceeds the predefined limit, the server will stop sending additional emails until the next hour starts. This is done to prevent misuse and ensure that the server's resources are shared fairly among all users.

Why It Matters When Choosing a Hosting Plan

  • Email Volume Needs: If your website relies heavily on sending emails, such as newsletters or user notifications, you need to ensure your hosting plan's sendmail limit can accommodate your needs. Exceeding the limit can lead to important emails not being delivered.
  • Business Reputation: Missing emails can harm your business reputation. Customers might not receive order confirmations or password resets, leading to frustration and potentially lost sales.
  • Scalability: As your website grows, your email needs might increase. Consider a hosting plan that offers flexibility or the option to upgrade your sendmail limit.

Common Misconceptions

One common misconception is that the sendmail limit only applies to spam prevention. While it's true that limiting emails helps prevent spam, it's also about managing server resources effectively. Another thing to watch out for is assuming that all emails will be queued and sent later if you exceed the limit. In reality, most hosting providers will simply drop the excess emails, meaning they won't be sent at all. Always check with your hosting provider to understand how they handle emails that exceed the limit.