Removed certs and used LE4ISPC script. Now the ispconfig is working fine without certificates warnings but MTA conections do ask for Security exceptions. Seems POSTFIX/DOVECOT certificates are not updated by the script
I think it's normal if the request is made for the first time to ns1.webologix.com and you simply need to confirm the certs. To check whether the certs are there, for postfix and dovecot, run "ls -lat /etc/postfix/smtpd.*".
Well I did not expect to be asked for security exceptions when I genrated certificates for postfix/dovecot. So I did accept security exceptions in my MTA and now I can send/receive mails so I'll consider the problem to be solved. Thanks a lot for your helps