EME advised to place the mails in a queue and therefore not to send them immediately (in the setting of Mail). What is the risk if I choose not to send in a queue? Because I would like to send the confirmation of RSVP immediately and not every 5 min for example
It depends on your email provider. If they limit you, then it will be a problem if you have a burst of emails being sent out due to many rsvp’s arriving at the same time. And it will also cause the sending of “generic mails” etc … to happen immediately.
There’s no EME issue though.