Cannot restore old emails

Please understand i am basically computer illiterate so be patient!
I have backed up my emails, contact etc.
When I then tried restoring them, they all reappear. THEN, it will tell me I need to log in again.
After doing that, it immediately deletes all the old emails, contact etc.
I can restore them every time, but then I cant see todays emails sent to me, I can’t send any emails either.
If i do log in, only today’s emails (since the backup) are visible, but no old emails or contacts.

PLEEEEEASE HELP

What version of eMC was used to backup up the emails?
What version of eMC were you restoring to?