Emails I send land in the wrong 'sent items' folder

I’m using Em client (along with Apple Mail) on MacOS 15.3.2 Seq

When I send an email it usually stores that mail in the sent folder (the one with the paper click icon to the left) BUT some emails that I send get filed in ‘Sent Messages’.

Any help would be welcomed

For whatever it’s worth, here are the basic rules I’m using to park sent mails. I do not use Exchange, Outlook, Apple Mail or any of those. Note that these rules get applied in precisely this order:

A detail regarding the first rule: I had attempted to set it to park those mails in particular in the Sent Mails folder, but it just wouldn’t do it, and it kept dumping them in the Archive folder. So as long as I knew where they were, I decide to let it decide…

When I send an email it usually stores that mail in the sent folder (the one with the paper click icon to the left) BUT some emails that I send get filed in ‘Sent Messages’.

I’ve never seen a Sent Messages folder and only a Sent folder under an iCloud mail account. The “Sent folder messages” might possibly be a eg: custom created folder to store sent messages outside of the normal account sent messages.

Check your account setup Sent folder under the IMAP Tab is set correctly via “Menu / Accounts”.

You can “uncheck” automatically detect special folders at the bottom and manually set your sent folder if it’s not the right Sent folder.