To set up your Yahoo email account in the iPhone Mail app:
fire up the iPhone parameters.
SelectMail>AccountsiniOS 14.
(SelectPasswords & Accountsin iOS 13 oriOS 12, orAccounts & Passwordsin iOS 11.)

SelectYahoofrom the menu that opens.
drop your Yahoousernamein the field provided for it and tapNext.
Enter yourpasswordon the next screen and selectNext.

Toggle the switch next toMailto theOnposition.
Optionally, also toggle the switches next toContacts,Calendars,Reminders, andNotesto theOnposition.
To do this:
On theHomescreen, tap theMailicon.

In theMailboxesscreen, tapYahooto open your Yahoo Mail Inbox.
Tap any email in the Inbox to open it and read the content.
Use the icons at the bottom of each open email to take action.

The icons representTrash,Move,Flag/Reply/Print/Forward, andCompose.
You don’t have to open each email.
You have other options.
