When there is a situation where the system is sending out a huge volume of emails at a time, you can set some system properties to avoid the mass email sending and any errors that could cause this.
We recommend not to modify the default values. However, on some cases, you might to slow down the default email delivery settings.
There are two properties you can use to control this:
The system checks for outbound emails using the SMTP sender scheduled job, and it'll try to send them out. If you activate the property glide.smtp.one.chunk.per.send, it processes the outbound mails in chunks. It will send out 100 emails at a time with brief pauses between chunks up to a maximum defined in the glide.smtp.max.per.job property. Once that max is reached, any emails that were claimed but are not sent get "unclaimed" and set back to send-ready. The email sending stops until the next time it is activated by the scheduled job.
You can reduce the total number of emails by enabling the property to send only one chunk and then shutting down for 1 minute or you can change the max per job setting to a lower number.
More information is available on our documentation