Is it possible to limit maximun of Outgoing messages Per Minute or create a separate email sending queue for high priority emails?Issue You have thousands of email notifications going out each day for all sorts our notifications. In the mix of this you have major incident notifications. You are looking for a way to have a separate fast track email sending queue or be able prioritise those emails within the bigger/single queue so that they always get sent as the first emails to sent next. Or you want to be able to throttle the SMTP sender job to limit the Outgoing messages to 30 Per Minute. This is because several email servers such as Office365 has this constraint for some domains.ReleaseAllCauseEmail technology has its own limitations and trying to delay or prioritise messages require further testing as it could cause unwanted effects such as sending unexpected information in the notification.ResolutionWeb Services seems like a feasible alternative for this kind of purposes as you can send information from ServiceNow to any server which will be reached by your users or will deliver with more priority your messages.Basically, there are some cases where the REST API has some advantages. These include:If your ISP is blocking all output mail ports, the REST API could be your only optionIf there is extremely high latency between your site and ours, the REST API can be quicker since it does not require as many client <-> server message / response interactions.If you do not control the environment that your application runs in, and it is difficult to install / configure an SMTP library More information about Outbound WebServices in our documentation page Outbound REST WebService If rest api is not feasible, you have to come back to your email administrator to have a configuration or service that allows a larger number of messages per minute.