Cant'send message cyberpanel

when i try to send a mail via snappymail and click send i get this error “cant’send message”.
the ports requested by cyberpanel are all open in my server.
ssl is installed on hostname.

• TCP: 8090 for CyberPanel
• TCP: 80, TCP: 443, and UDP: 443 for webserver
• TCP: 21 and TCP: 40110-40210 for FTP
• TCP: 25, TCP: 587, TCP: 465, TCP: 110, TCP: 143, and TCP: 993 for mail service
• TCP: 53 and UDP: 53 for DNS service

Look here your question was asked and there are answers to it Can't send out email using cyberpanel rainloop - #3 by maxb