suddenly 'User unknown'?

[Charles Bradshaw]

Is my TLS configuration correct?

/etc/imapd.conf contains:

tls_cert_file: /etc/pki/cyrus-imapd/cyrus-imapd.pem
tls_key_file: /etc/pki/cyrus-imapd/cyrus-imapd.pem
tls_ca_file: /etc/pki/tls/certs/ca-bundle.crt
tls_cipher_list: TLSv1:SSLv3:!NULL:!EXPORT:!DES:!LOW:@STRENGTH

Files exist:

[root at dell2600-1 brad]# ls -l /etc/pki/cyrus-imapd/cyrus-imapd.pem
-rw-r-----. 1 root mail 3242 Apr 12  2014
/etc/pki/cyrus-imapd/cyrus-imapd.pem
[root at dell2600-1 brad]# ls -l /etc/pki/tls/certs/ca-bundle.crt
-rw-r--r--. 1 root root 754217 Feb 28  2018 /etc/pki/tls/certs/ca-bundle.crt

Is the tls_cipher_list still valid??

CUT: