I sent an emal with an attachment, no body to my personal email using the school computer, i used google incognito mode, can the email be retrieved?
If the email was sent through the browser using gmail and sending to your gmail, web traffic log files will show the connections, but not sure they'll indicate whether or not an attachment was included. They only way to retrieve the email would be by logging into your gmail account.
However, if you sent it through a browser logging into the schools email server, yes, the email and the attachment are probably temporarily stored on the email servers. It's anybody's guess as to how long they'll be stored.