As I am unfamiliar with the Mac Version, I apologise I cannot assist you. I would ponder that it basically functions the same as it does for Windows? In addition, for your own Safety (Spam), and privacy. Please refrain from posting publically your personal Email Address.
I might add, can you open the McAfee UI, and go to Navigation/quarantined/trusted items/and delete?
All the very Best,
Your login has been changed you will get an official email re it soon so until then note your login is your old 1 minus the @ and what comes after it.
If you have any worries about your imac call tech support and ask for mac support as we mods do not have any Macs to work with.
Moved this to MAC products for clarity.