I'm using dovecot 2.2.36 on CentOS 7.7. My configurations are (dovecot -n):

disable_plaintext_auth = no first_valid_uid = 1000 mail_location = maildir:~/Maildir mbox_write_locks = fcntl namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } } ssl = required ssl_cert = </etc/pki/dovecot/certs/dovecot.pem ssl_key = # hidden, use -P to show it

I want to disable accounts for system users. Only virtual users will have accounts (not configured yet). Is this possible?

Thanks, Mura Andrei