You cannot add a CNAME for a root domain. The DNS standards state that a CNAME is replacing any record for the host. SO if you add a CNAME for example.com then adding any other record for example.com is useless because it will be ignored. If you remove the first CNAME record the MX records should start working (after the dns changed get propagated).
So, please add a CNAME record for your domain as www.domainname.com and then you can add an URL forwarder for domain.com forwarding to www.domain.com
To add the CNAME record,
- Login to your account,
- Click on your domain name, under advance options, click on "Modify Domain Setup",
- Here under "DNS" tab
- click the "ADD NEW DNS RECORD" button or scroll down and you will see a "ADD NEW DNS RECORD" section and here add CNAME record like below
- In the NAME field enter www, and in the Canonical Name enter CNAME Value, e.g. web.me.com, ghs.google.com, zmverify.zoho.com, etc.
Once done, click on 'Save' and then click on 'APPLY NOW" button