IMAP via Outlook 2021 not keeping copies of sent

[russ]

I have verified the check box for "saving copies" in the Outlook options section.
and have not changed any settings in over 2 weeks.
but staring today when sending messages no copies are retained.
On same account and IMAP on phone (bluemail) everything is fine.
Is it me or are others seeing this?

[russ]

could be my folder size is 2.4G. I suppose Archive is in order