If many Notification emails are sent out at the same time, some of them will be stored under (Service Desk Manager)\site\mail_queue folder and wait for the next trigger to connect to a mail server.
How often does SDM connect to the mail server to send out the emails? Can we change the frequency of the connection?
There is no setting of mail server connection interval, i.e. we are not able to control how frequently Service Desk Manager connects to a mail server.
When many emails are sent out and a value of the option mail_max_threads is reached, all threads status will be set to "Busy". Once the status is changed from Busy to "Ready", the emails stored under the mail_queue folder will start to be sent out.