I have the following showing up over and over in the Zimbra log. I'm wondering if anyone knows what the cause and effect is.

Code:
Mar 19 06:52:10 zimbra postfix/smtpd[10672]: warning: cannot get RSA private key from file /opt/zimbra/conf/smtpd.key: disabling TLS support
Mar 19 06:52:10 zimbra postfix/smtpd[10672]: warning: TLS library problem: 10672:error:0906406D:PEM routines:PEM_def_callback:problems getting password:pem_lib.c:111:
Mar 19 06:52:10 zimbra postfix/smtpd[10672]: warning: TLS library problem: 10672:error:0906A068:PEM routines:PEM_do_header:bad password read:pem_lib.c:454:
Mar 19 06:52:10 zimbra postfix/smtpd[10672]: warning: TLS library problem: 10672:error:140B0009:SSL routines:SSL_CTX_use_PrivateKey_file:PEM lib:ssl_rsa.c:669: