To access Windows 10/11 Mail settings click the icon - you will then see the following menu appear - all the important options are explained below

Manage accounts |
Click here to add an email account - see here for more detailed instructions, or to remove an account |
Personalisation |
Change colour scheme and background image |
Automatic replies |
Configure a reply to be sent automatically to all emails received |
Focused inbox |
Allows you to turn off Focused inbox which is where all important mail appears in Focused folder and the rest appears in Other folder |
Message list |
Configure tablet swipe options, and choose whether to show preview of messages, show messages in conversation style and whether to show images |
Reading pane |
Choose whether to mark items as read once viewed in reading pane, and whether to automatically open next item |
Signature |
Create or edit the text which appears on the bottom of all emails you sent |
Default Font |
Choose the default font style and size for displaying your email content |
Notifications |
Choose how you wish to be notified of new emails e.g. sound or alert banner |
Email security |
Settings for digitally signing and encrypting emails - only for accounts which support S/MIME |
What's new |
Click here to show what is new in the latest update for Windows 10/11 Mail |
Outlook for Android and iOS |
Takes you to a website where you can send a link to your phone to download the Outlook app |
Help |
Enable diagnostic logging - for troubleshooting use only |
Trust Center |
Allows you to enable / disable online services such as showing locally relevant content in the app |
Feedback |
Opens Feedback Hub tool to allow you to submit feedback on problems or usability issues |
About |
Show what version of Windows 10/11 Mail is installed |