@ jenpen
Email folders are somewhat different to regular windows folders, most email clients contain emails in a database 'file' this contains multiple emails but is essentially a single file.
I suspect that this detection was on an on-demand scan ?
If so which type of scan, Quick, Full Scan, Folder Select, etc.
So first what action was taken, Send to chest should mean that the database file is in the chest ?
If you chose delete then it is gone and you will have to resort to your backups to restore that file, you do backup your system.
What is your email client/program ?