Can Domain Name Contain Underscore. It is also known as a domain name extension. Do not use periods in new NetBIOS domain names.
Such certificates MUST NOT be valid for longer than 30 days. If you try to register a domain name with underscores many Domain Registrars will remove the underscore before you can register that domain name. If you are upgrading a domain whose NetBIOS name contains a period change the name by migrating the domain to a new domain structure.
Learn more about top-level domains here.
My domain does not have an underscore in the DNS name mycompanylocal. I personally advise Bluehost as well as will certainly experience the actions you require to require to rise and also running. Symantec Messaging Gateway SMG does not accept messages when envelope sender or recipient email address es contain underscore character in the domain name. The use of underscores in hostnames violates RFC 1123s valid defined characters for a domain name.