Send throttling allows you to select a range of hours during which you want to send your email. Use send throttling to:
- Manage the time of day your emails are sent.
- Control inbound traffic to a website. This is helpful in instances where an email message results in a large number of people visiting a website, which could potentially cause a server crash.
- Limit the number of messages sent to a particular domain each hour.
If your list contains over 100 external email addresses, you should use send throttling.
When sending an email message, under Schedule Send, check the box for Send Throttling, and select a start time and end time. Specify a limit of how many messages per hour to send, if desired.
After you send the message, the system processes the email send job at the start time you specify. The system will continue sending during the specified time range until the send is complete or the specified end time is reached, whichever comes first. Subscribers are processed according to their order in the subscriber list. The system starts at the top of the subscriber list and works to the end. The sending pauses if the hourly limit is reached or the time window closes. The send resumes when the throttle opens again. This process continues until the send is complete.
Note: Setting a throttle for a job does not ensure that a certain number of email messages will be sent during a particular time period. The throttle ensures that the system will not send a greater number of messages than the throttle limit during the specified time period. The system may send fewer messages due to system load, message complexity, or deliverability issues.