Sometimes I see some postfix warnings in my mail.log file:

Code:
warning: cannot get RSA private key from file /opt/zimbra/conf/smtpd.key: disabling TLS support
Mar 11 06:40:31 mail postfix/smtpd[20084]: warning: TLS library problem: 20084:error:0906406D:PEM routines:PEM_def_callback:problems getting password:pem_lib.c:111:
Mar 11 06:40:31 mail postfix/smtpd[20084]: warning: TLS library problem: 20084:error:0906A068:PEM routines:PEM_do_header:bad password read:pem_lib.c:454:
Mar 11 06:40:31 mail postfix/smtpd[20084]: warning: TLS library problem: 20084:error:140B0009:SSL routines:SSL_CTX_use_PrivateKey_file:PEM lib:ssl_rsa.c:669:
I searched on the internet what to do, but the only thing I found is to edit the main.cf file (postfix). When I edit the main.cf file, and restart postfix, everything change back to the default settings (I think the settings from Zimbra)...