setup Sent folder in sidebar

This article from Apple on Setting up Favourites in Apple Mail has the needed information

Use favorite mailboxes in Mail on Mac - Apple Support (CA)

markdrolc wrote:

Thanks for your reply P. Phillips but I can't see how this info will help get my sent emails into the new folder named "Sent Items" in my sidebar?

Where are the missing message located presently ?

Is the e-mail Provider using IMAP Protocol ?

Is the e-mail Provider using SMTP Protocol ?

If using the IMAP Protocol - what is appearing on the Web Portal of the e-mail Provider should be mirrored back to the Mail Application.

Have you Logged into the Web Portal of the e-mail provider and checked if the missing e-mail are appearing in a Sent or similarly name Folder ?

Thank you.

Should have Corrected Myself 😔 - should have written POP and not SMTP

POP Protocol would Remove the e-mails from the Server.

This would effective place the mails ON the computer ( Locally Stored ).

You may what to check in the Mail Application for a folder called " On My Mac " if one should exist

Add On

Welcome and thank you too for the Moniker of Best Answer