Deleting emails can be a boring process on the iPhone, especially since the "Trash All" options have been removed since iOS 10 first came out. While it is likely to be deliberate, this change imposes an unreasonable burden on all of us iPhone owners who now have to delete emails individually.
Delete them individually can be compared to a significant amount of wasted time – check out the video below if you don't believe me, which is true for iOS 10, iOS 11 and iOS 12. Thankfully, it's a little known bug that you can still Use to delete all unwanted emails at once.
This simple trick will work in any of your email folders, whether flagged or unread. So if you're interested in deleting spam a lot, I'll show you how to exploit this dirty bug, as it could go off with the arrival of future iOS updates (however, there have already been three major iOS updates so far) .
To begin with, go to a folder you want to clear unread emails from mailboxes . It can be a default folder for each account like "Inbox" or "File" or a folder you created yourself.
Once inside, if you want to get rid of everything in that folder you don't have to filter it at all. Go to Step 2 if it is your case. Otherwise, if you want to be more selective, tap the icon with three rows of filters at the bottom left, where you can dress your inbox by selecting either "Unread" or "Flagged" from the Include section.
If you want to grab everything, you can also select "To: Me" and "Cc: Me" under Addresses . All filters or combinations of filters on the page will work. In my example, we just delete all unread emails from the folder.
Step 2: Save All Desired Emails
The next thing you want to do is check if there are any emails you want to keep, then scroll through the filtered view so that you do not remove anything important. If you find something you don't want to delete, there are several things you can do.
Select the e-mail message, press the folder button at the bottom and then move to a different mailbox. However, it will inadvertently mark the next e-mail as read because it automatically shows it, so you need to mark it as unread before continuing. Therefore, it is better to use the option, which also allows you to save multiple emails at the same time: Press "Edit" at the top right of the folder view, select all emails you want to keep, then press "Move" and select the appropriate folder .
Drag to the left of the e-mail message to reveal the extra options (•••) button, press it and select it as read. If you have multiple emails that you want to mark read, press "Edit" at the top right of the folder view instead, select all emails you want to save, then press "Select" and "Mark as read." Then, since they do not disappear from the filtered list as they do when moved to another folder, you must press the filter button at the bottom left to leave the filter and then press it again to return to the filtered view  How to remove bulk e-mails from your iPhone's e-mail program ” width=”222″ height=”222″ style=”max-width:532px;height:auto;”/>