MacOS Monterey: Mail>sent mail folder: How do I display recipients in the main window?

Q - BTW: How does Mail know when the recipient has received an email? dont you have to send it in a special format ( like a certified letter) to get confirmation of receipt? "

A - AFAIK there has never been a Feature like that in Apple Mail and this goes back to around 2004 - 2005 with OSX 10.4 Tiger .

A - Beside that, if I were to receive a " Request of Receipt " for an e-mail I would not confirm that. It no bodies business if I Receive or Read an e-mail

A- If the information. is that important to the Sender - Messages Application does provide the Send Receipt Function or better still Call on the Phone and discuss the Importance of the e-mail

I don't know why your Sent folders aren't switching to To like everyone else's. I don't know of a setting, but maybe somewhere.

Collumn View. Is that what you mean? There is a column for: Flag, Paper clip ( attachment), a blue to if not read, From ( always me! who needs that?! — this is the "sent Mail" box), Subject, Date received, Size...

You can ctrl-click on the column headers and add/subtract whatever columns you want.

Building on previous posting and Column View >> Header and Control Click >> Sub Menu presented

What format are you viewing the emails in?

Here's what I get:

How are you viewing them?