aaP_daichikei12 Hello. How to solve port 25 is closed, even though after I checked it was open in the dns checker.
aaPanel_Kern Hello, try gmail, if still can not suggest consulting the network provider or server provider centos: yum install telnet -y && telnet gmail-smtp-in.l.google.com 25 Debian/ubuntu: apt install telnet -7 && telnet gmail-smtp-in.l.google.com 25
