[Dovecot] Unknown password scheme SSHA512

Hello,

I installed dovecot via Debians apt package manager. The passwords are stored as SHA256 hash in a PostgreSQL database. default_pass_scheme in dovecot-sql.conf is set to SHA256. However, smtp-auth fails.

Jul 24 00:31:07 smtp01 dovecot: auth(default): sql(mail@jasbafliesen.de): Unknown password scheme SHA256

Can anybody help me?

Regards Patrick