configuring new exchange certificate 2010 is not valid smtp

Hi

while configuring  new exchange certificate on 2010 got error is not valid smtp  xyz (host name ) my domain name is xyz.local

Microsoft Corporation
Microsoft® Windows® Operating System
6.1.7600.16385
"xyzl." isn't a valid SMTP domain.
Microsoft.Exchange.Data.StrongTypeFormatException: "xyz." isn't a valid SMTP domain.
   at Microsoft.Exchange.Data.SmtpDomainWithSubdomains..ctor(String s, Boolean includeSubdomains)
   at Microsoft.Exchange.Management.SystemManager.SmtpDomainWithSubdomainsMvpExtension.InsertDomain(MultiValuedProperty`1 domainsList, String domainName)
   at Microsoft.Exchange.Management.SnapIn.Esm.Servers.NewCertificateBestPractice.DefaultDomainNamesGenerator.FillOwaDefaultDomainNames(MonadConnection connection)