Good day...
I have problems with the email, I can receive mail but I can not send them, I'm using Sentora Panel mailer with RoundCube.
A hug

MX records define what email servers are responsible for receiving emails for your domain name. The problem with not being able to send emails is not related to MX records. It is possible that your ISP is blocking outbound port 25 to prevent from sending emails. You may use SMTP Outbound Relay service at https://www.dynu.com/en-US/Email/Outbound-SMTP-Relay to send out emails using our relay server.