How to See Full Header in Outlook Mail Online? (2018)

A simple workaround would be to temporarily move all of your deleted messages to a new folder ("Zombies") and search within that. Then, when you're done with whatever you're moving about, just delete the folder, which will (once again) delete all of the messages within it.

Unfortunately, this is not possible at this time.

You can (directly within the email interface), add a new contact if the contact is the sender of the email (the "From" field). However, the contacts in the cc and bcc cannot be directly added to your contacts.

The quickest way of doing this individually for those 30 contacts you have would be to use the desktop version of Outlook (tested with Outlook 2013). Within here, you can hover on each persons email to add them to your contacts and then add them to the group.