What error did you got when trying the recreate the domain?
Check the logs for additional information.
When deleting an email domain some things are preserved:
Warning. If domain.tld is deleted, this server will reject new messages for that domain. However any message that has been already delivered is not affected and will be preserved.
Most settings are stored in an e-smith database. You probably will need to check for remnants from a terminal console (maybe some settings in dovecot and postfix).
To list configured domains:
config show domains
To identify the e-smith database holding remnants of the domain you can use grep:
grep -ri domain.tld /etc/e-smith/db/
Do not manually edit those files, use the appropriate commands instead (usually config and db commands).