As many admins have checked "Send Original Mail to User Also" in advanced content control it would be very useful to have the option "Add Senders Email-Id to Whitelist" in "Mails In Quarantine".
At this time there is only the option "Release selected mails" - when using this option the mail is received twice.
The reason why the admins use "Send Original Mail to User Also" (normally with [SPAM] in subject):
1. The user gets all mails - spam is forwarded into a spamfolder - and the user can easily check his spam folder with his mailclient on a regular basis. So no wrong as SPAM categorized good mail gets lost.
2. The admins do not trust their users to login into webadmin on a regular basis to check the mails in quarantine - this means that some important mails might get lost if not directly delivered with "Send Original Mail to User Also".