Deleting bulk emails

Once you've downloaded it and signed in, find the box you want to go into like your inbox, double tap on it, then tap and hold on a message, you'll then enter an editing mode, you now will need to tap on each message to select it and after that's all done, you can delete them.

There might be a select all button or something but i'm not entirely sure.

Personally I find thunderbird on windows to be easeier as I just have to select what I want then press delete.

You can delete the entire contents of a mailbox in iOS Mail, though I would advise caution. However, to do this:

1. When inside any mailbox (Inbox, Flagged, Archive, Junk, etc), double tap on "edit". Starting from the top-left of the screen, flick once or twice to the right.
2. Double tap on "Select All". Top-left corner.
3. Now you can use the controls on the bottom of the screen to Trash/Delete All, Move, Mark, etc, etc.

Alternatively --
If you have a select number of emails you wish to delete within a mailbox:
1. From within the mailbox, choose "edit" as listed above.
2. Manually double tap on all the emails you want to delete, they will be marked as "selected" by VO.
3. Use controls at the bottom to trash, etc as listed above.
4. (Optionally) If you do not find a trash/delete control as stated in step 3, choose the "move" option and just manually move your selected emails to the trash mailbox.

HTH.