Migration from Centos 6 to 7 Postfix problem

Migrated from Centos 6 to 7, but having a problem with Postfix. Problems: -Mail arrives to the box and can be read via webmin, client keep popping up asking for correct password! No record of any attempts to collect mail in Webmin -Postfix only started to work after external IP was changed to correct one (it was set to some generic VPS ip address) -Spamassassin/ClamAV don't seem to work Would that be possible for Andreycheck or someone to have a look at it quickly, because all in all it looks like mystery (and I have not changed anything apart from IP address in Postfix settings). Kind regards!