Deleting All Emails all at once, I just am too stupid to find it

Question

I hope somebody can tell me I'm a dunce who has totally missed something obvious. I get over 50 emails a day. I have to delete them ONE AT A TIME! Then they go to trash and I HAVE TO DELETE THEM ONE AT A TIME AGAIN! I know there has to be a better way, I am just too stupid to find it. This is so irritating, I'm considering turning off the email unless I'm out of town or something. How do you empty the inbox ALL AT ONCE!?! Or at least the trash ALL AT ONCE??!!
If by some weird fact of programming blind idiocy, there is no way to do the most basic thing I am talking about, which is common to every phone email system on earth, would the wise programmers at Apple do an update tomorrow so that we can EMPTY THE INBOX IN ONE MOVE, PLEASE!!!!

Answer 1

A POP account is designed to be accessed with an email client such as Apple's Mail application on one computer or device only.
New messages received at the incoming mail server for a POP account are downloaded by the email client used to access the account with an option to remove messages from the server after being downloaded. Sent messages with a POP account using an email client cannot be stored on the server.
An IMAP account is designed to be accessed with an email client on multiple computers or devices with the ability to store all account mailboxes on the server - the account's Drafts, Sent, Trash and Junk mailboxes with each email client used to access the account and the ability to create additional server stored mailboxes with the email client used to access the account - with the exception of the iPhone's email client. You cannot create additional server stored mailboxes from the iPhone's email client but any additional server stored mailboxes created with the email client used on your computer to access the account will become available with the iPhone's email client automatically.
All messages with an IMAP account remain on the server until deleted from the server - there is no setting to remove messages from the server when received by the email client used to access the account. All server stored mailboxes are synchronized with the server automatically with the email client used to access the account.
Receive a new message with the email client used on your computer and read the message, when checking the account with the iPhone's email client, that message will be available in the account's Inbox mailbox and will be marked as already being read since the account's Inbox mailbox stored on the server is kept synchronized with the server automatically. Delete a message from the account's Inbox mailbox with the email client used on your computer and this message will not be available when checking the account with the iPhone's email client. Send a message with the email client used on your computer and the sent message will be available in the account's Sent mailbox with the iPhone's email client automatically and vice-versa for all.
If you are accessing an IMAP account, instead of deleting all messages from the account's Inbox mailbox with the iPhone's email client one at a time, you can delete all from the account's Inbox mailbox with the email client used to access the account on your computer and all messages will be automatically removed from the account's Inbox mailbox with the iPhone's email client since all server stored mailboxes are kept synchronized with the server with the email client used to access the account.
Someone has a desktop at their office and a laptop when traveling or when away from the office or in your situation accessing the account with your computer's email client and with the iPhone's email client. An IMAP account provides for keeping all account mailboxes synchronized automatically between multiple computers or devices to access the account.