Emails from iSAMS on our system go out via Send Grid. If, for some reason, iSAMS is able to generate the email, but unable to forward it to Send Grid, that email is logged as failed with the Email Manager applet in the Control Panel.
However, the email still appears in the Communication History section of the Pupil Manager module.
That is not actually a bad thing: when troubleshooting emails, it is helpful to use this section of the pupil record to see that the such an email was sent at a specific time to this pupil/parent. (Using the Email Manager section in the Control Panel is much harder when considering specific cases.)
However, there is nothing to indicate that the email in question didn't actually get successfully sent.
It would be great if the logging of the email in this section of the pupil record made explicit the fact that the email was not successfully sent.
See also ticket #744829. We had a case where important information about a pupil was being sent to the teachers, and the head of year was not aware that isams hadn't sent it because the attachment was too large. This was from the wizard bar. If there had been a clear message that the attachment was too large, then he could have sent it straight from Outlook.