If you could please consider the following mail suite updates, I would greatly appreciate it.  If you have any of them in test or beta mode or anything that I could use, that would be great too.  Thanks!

1.  What happened to sort by subject and sender?  These are so important! Please bring them back!

2. It would be great if, in addition to restoring the sort by sender and subject options, you could also enable sort by folder after a search is done and there is a folder column.  And, if there was the option for a "to" field column when viewing mail so you could see which email address/alias each email was sent to (and of course if this field was also sortable)

3. Drag and Drop folders are a great feature that you recently added.  But, is it possible to add a "lock folders" option that would prevent folders from being accidentally dragged and dropped inside each other and prevent the order from accidentally being changed?  With so many touchscreen devices, it is really easy to accidentally move folders and have them disappear into other folders without noticing.  With a lock folders option, you could easily arrange your folders however you want with drag and drop, and then lock them so you can't accidentally drag them.  If you wanted to make changes to the folder structure, it would be as easy as unlocking the folders, moving them around, and re-locking them.  

Or, just add an option to the setting where you can currently pick between alphabetize and preferred sort that is something like lock folders.  And for people who don't have this issue and want the flexibility of dragging folders without unlocking them, they could just not set their folders to locked.

Thank you very much!