How do you insert MX record without subdomain?

[MaXi32]

I have this requirement to add an MX record without subdomain using the GUI below:

So I leave the field (after value 10 as a blank field to represent it does not have a subdomain) but, when I try to add the above record, it showed me this error:

Cannot Add Record​

You must provide a valid name and value

Is there a special symbol that can represent this blank field? Tried the dot symbol it works. But is it a valid representation of an MX record without a subdomain?

 

[Richard G]

So you want to use domain.com instead of mail.domain.com correct?

Try this. After Value 10, put in this:
domain.com.
mind the trailing dot. Should work this way.

 

[MaXi32]

So you want to use domain.com instead of mail.domain.com correct?

Try this. After Value 10, put in this:
domain.com.
mind the trailing dot. Should work this way.

Thanks, I'll follow this way.