you could go to System Settings → Accounts and uncheck the Mail sync type for the /e/ account. There are lots of screenshots in this thread, but you see what I mean with “Mail” sync type in the second row, first shot to the left, below the yellow encircled “Carnets d’adresses” - [HOWTO] Use the Account Manager - #6 by MIB
if this doesn’t work and the account reappears it’s a bug