Either run the guide for "Email Accounts" or "SMTP Mail Setup", you don't need both!
"Feature Update: Enhanced email capabilities" needs to be disabled in feature management for you to find the assisted setup bellow.
Setup E-mail via "SMTP Mail Setup"
In Business Central, search and go to the page 'Assisted Setup'
In 'Assisted Setup', click on 'Set up outgoing email' if its not already Completed.
(If this is already Completed, you can jump to the 'Initialize' page)
Select the email provider, pictured will be a set-up of ‘Other Email Provider’ using SMTP.
Fill in the email account details and then click next when you are done.
Click finish to complete the set-up of E-mail communication. If you need to verify your settings, you can click ‘Send Test Email’ and check if it works. If not, you can go back and check the entered details.
If you have problems setting up your SMTP, please contact your BC partner to help you with this.
Move on to 'Initialize' when you have a working outgoing e-mail.