If you are an email user, you have definitely come across this notorious term— SPAM. Spam mails, also known as junk mails, are unsolicited electronic mails sent in large quantities that consume the server resources and network bandwidth.
Spam mails can be annoying. However, in some cases, they are not sent intentionally. A user’s computer may be infected with viruses, causing it to send out spams using his/her email identity to random people or, most likely, people in his/her address book. Sending out spam mails can affect the user’s server’s reputation, causing it to be blacklisted or blocked by other email service providers. There is a need to control and hold the spam mails before it is delivered out. This is due to if the user’s email server is blacklisted, the user’s email will be blocked and could not reach their intended recipients in the future until it is whitelisted.
Email sending limits
Therefore, in order to ensure your accounts safety and our system’s health, there is a limit of 1,000 email a day per domain allows to relay (to send out). This quota is reset at 12:00 AM of each day. If you have hit this quota, you will have to wait until the system reset the quota for the next day. The incoming email traffic is not affected.
If you were getting this notification, you may not be the person consuming all of the allocated email in the domain. It is just that everyone in the domain has been blocked with the outgoing traffic.