Then select each e-mail. A blue dot will appear.
GO TO THE BOTTOM OF COLUMN. Hit delete.

You can delete a bunch at one time. Not as easy as selecting all, but easier than sliding the delete thing one at a time. Don't forget to empty the trash once in a while, too.

Note: this is for an iPad, but it should be similar for an iPhone.

Yeah, easier than the slide, but still a huge pain. I often have 75 to 100 emails several times a day.

Even the Apple Store kids admit it is a pain.

My favorite trick is to mark a bunch and then go to the top and hit cancel instead of going to the bottom to hit trash. Then I have to mark them all over again. Gah!

http://www.conferencesthatwork.com/index.php/technology/2014/01/how-to-delete-all-mail-messages-from-iphoneipad-in-one-step/


How to delete or move ALL emails at once in non-jail broken ipad or iphone

It took me weeks of research to figure out finally how to decode this yet another secretive secret of apple. There is a perfect way of deleting ALL emails at once without jailbreaking your iphone or ipad…and here it is:
>> Open Inbox >> Edit >> Mark All >> Mark As Read [Added May 21, 2014 by Adrian; this extra step makes the difference between success & failure for some.]

>> Open Inbox >> Edit >> Check/select the top message; it will highlight the move button.

>> Press and hold the move button and uncheck the message that you had checked earlier.

>> Lift all your fingers off from the ipad screen and leave it alone. Wait until all your messages pile up on the right hand portion of the screen (in ipad); iphone will give you the actual number of emails it has selected for the action. Now they are just waiting for your command to be moved ALL at once.

>> Choose trash to delete all of them or any other folder where u want to move them, like one piece. Remember this will replicate your action on the server so you will ACTUALLY move them or delete them on the server and not just the ipad.

Once you have moved all messages to the trash you can either leave them there for the scheduled cleaning or empty it right away by doing this: go to trash folder and touch Edit. The Delete All button shows up at the bottom of the screen. Hit it! You’re done!

If you do not see the effects of your actions on the server make sure you have enabled your email accounts for such actions.

Tips:

1. Please give enough time (could take up to several minutes depending the number of emails to be moved) for the emails to be selected for the move. Your screen will become unresponsive while all emails are being packaged. Once emails are ready, in ipad, you will see them zoomed out on the right hand side of the screen, and in iphone you will see the message showing you the actual number of messages that have been selected.

2. Avoid purging very large number of emails, the mail app might freeze or crash. If your inbox has thousands of emails change your sync settings in mail settings to fill lesser number of emails in your inbox.

3. [Added Jul 20, 2014 by Adrian] Many people have reported needing to repeat the above procedure several times before it succeeds. (I too have found this to be necessary a few times on my iPhone but not on my iPad—go figure.) So my final tip is to repeat the procedure 3-4 times if the mail doesn’t disappear the first time. In my experience, if your messages disappear momentarily and then reappear, repeating the procedure will eventually make them stay deleted for good.

I've read that tip and tried it any number of times. It appears to work but after doing it all the "deleted" emails are back in my in box. I could be doing something wrong, but can't figure out what.

Add another tip to the list of tips to be followed to get it to work. I have my phone and iPad set up to get mail from five different accounts. I have been trying to delete all mail from all mailboxes from the "All Inboxes" screen. That always failed. However, following the instructions for one inbox at a time works. You also have to be sure to allow enough time and not play with the screen until it does what it needs to do.

I had over 28,000 emails on my phone. They're all gone now.

I read something to the effect that people think Apple took the bulk erase away from the newer OSs because they don't want you accidentally erasing all your saved emails. Not sure that's true.