Outbound Email Limits
You receive error "Your Salesforce organization’s daily limit for outbound emails has reached."
This error occurs because using the API or Apex, you can send single emails to a maximum of 5,000 external email addresses per day based on Greenwich Mean Time (GMT). Please see the details here.
Note: If you send one email to 5 recipients then 5 emails would be counted towards your daily outgoing emails instead of 1.
You can also contact Salesforce support and ask them to increase these limits. Salesforce can increase limits for individual customers (on demand) if they describe their use case and justify the need for increased limit.
We provide an alternative to use an external email service to send outgoing emails that do not count toward Salesforce Email Limits. If you want to use it then please have a look at the Email Gateway option in e2a Global Settings and use/configure Mailgun as described on our help site here.
Please contact us at firstname.lastname@example.org for any questions.