Sent read receipts not archived in sent mail folder

In some old topics of this Forum I read that eM Client saves the sent read receipts in the sent mail folder, without the possibility to disable this feature. Well, I have the opposite problem: read receipts are correctly sent but are not stored in the sent mail folder (they seem to disappear into thin air after sending). In eM Client’s release history I have not found anything about removing this feature. Unlike other people, I would like to keep track of the sent read receipts ;-). Please, can you give me some explanation / solution to this problem? I use eM Client 7.2.38682.0 Free Edition (for two POP3/SMTP accounts) on Windows 10 Pro. Thanks, regards.