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Proofpoint, Inc.

Common errors related to limits for sending and receiving email

Situation The customer is receiving an error message referring to the amount, speed, or size of undelivered email.
Solution See below to discover why the error occurred and possible resolutions to the problem.

To ensure the ongoing health of our platform, Proofpoint Essentials imposes limits on:

  • The number of messages sent and received
  • The number of recipients per message
  • The size of a message.

Look at the error messages below to identify your issue and learn ways to avoid these problems in the future.

You have reached a limit for sending mail

  • You may see this message if you send more than 500 emails in a 10-minute period or if you send more than 2,500 emails in a single day.
  • When you get this error, you should be able to send mails again within 1 to 24 hours.

The user you are trying to contact is receiving mail too quickly

  • You may see this error if the recipient has received too much email. Your emails are only momentarily deferred and should be delivered without any additional actions.

Too many recipients

  • You may see this message if you send an email to more than 1,000 recipients in a single email.
  • When you get this error, you may need to send multiple emails in order to reach all recipients.

Message size exceeds file system imposed limit

  • You may see this message if you send an email that exceeds the recipients maximum file size.
  • When you get this error, you may need to find an alternate way to share the email contents with the recipient(s).

Emails are being delayed or deferred

  • You may see this error when the Essentials recipient has received the maximum allowed emails per minute. If a user is the subject of a large quantity of email being targeted at their address, we will process this over a longer period. 
  • Keep in mind that inbound limits are as follow:
    • For registered accounts is 200 messages in 60 seconds
    • For unregistered accounts (SMTP Discovery) in a domain there is a 500 message limit in 60 seconds (at the domain level).