Problems with CNAME and MX Records (conflict)

Problems with CNAME and MX Records (conflict)

Hi guys,
Im having a problem at my zoho mail. It was working so good before I change my forwarding domain to zohosites. Now it seems my cname and mx records have same configuration and it does not allow me to update mx records. My webmail does not receive anymore emails, but is sending emails.
My mail is contato@gtasst.com and my domain is www.gtasst.com .
Could you guys help me? What is wrong?

Scs,

GTA