See the limitations for sending mass emails.
You can send mass email to a maximum of 5,000 external email addresses per day per licensed Salesforce org based on Greenwich Mean Time (GMT).
The following limitations also apply to mass emails.
- You can send mass email and list email to a maximum of 5,000 external email addresses per day per licensed Salesforce org. A day is calculated based on Greenwich Mean Time (GMT).
- The single email, mass email, and list email limits count duplicate email addresses. For example, if you have johndoe@example.com in your email 10 times that counts as 10 against the limit.
- API or Apex single emails can be sent to a maximum of 5,000 external email addresses per day.
- You can send an unlimited amount of email through the UI to your org’s internal users, which include portal users.
- You can send mass emails and list emails only to contacts, person accounts, leads, and your org’s internal users.
- In Developer Edition orgs and orgs evaluating Salesforce during a trial period, you can send to no more than 10 external email recipients per org per day using mass email and list email.
- You can’t send mass email using a Visualforce email template.
