SMTP Email Relay Limit

Mailprotector's outbound systems are designed for human generated messages for direct person to person contact.  Any outbound messages should be directed towards recipients with which you have a prior business relationship, have specifically requested contact, or have included their address in your distribution list on a double opt-in basis.

For newsgroup and mass mailings, we recommend a third party service such as Campaign Monitor, Mail Chimp or other services designed for this type of outbound relay.

Mailprotector email send limit - maximum 1000 recipients / emails per hour

Your email account includes 200 SMTP relays per mailbox, per hour. Each address listed in the CC and BCC fields count against your daily limit. One relay consists of an email message sent to one address using the SMTP service. Therefore, you can send up to 200 messages per hour, per mailbox. Your SMTP relay limit resets once each hour.  If the limit is reached, messages will stop sending for the remainder of the hour. Mailprotector systems will resume sending messages once the hour expires and new one begins.

Number of Addresses 

Exchange+ mailboxes are limited to 500 recipients on any single message. Any more than this, and the message will be rejected with an error.

Web-Based Email does not limit the total number of messages you can send per hour; however, there is a limit of 20 addresses on a single email message. The 20 addresses may be included in any combination of the To, CC, and BCC fields. If there are more than 20 total addresses, the Compose window shows an error and the message is not sent. You must revise the recipient list and then resend your message.

Mailprotector outbound SMTP size limit - max 150 MB per message.  Note: This number includes text, HTML, images, and attachments.

Have more questions? Submit a request