postfix/dovecot/mysql mailserver outlook outgoing emails
I run postfix/dovecot/mysql mailserver for about 6-9 months, it' already two weeks that outlook constantly warns me about invalid certificate and does not send emails (thunderbird works fine). My certificate is the dovecot default, so do I need to do anything to solve this out? any help will be appreciated.
It sounds as though you are experiencing an issue with Outlook disapproving of self-signed SSL certificates. The only way to resolve this (as far as I know) is to either add an exception for the self-signed SSL certificate in Outlook or to purchase a commercial SSL certificate for your mail server.