intermittent failure of smtp from c# code

intermittent failure of smtp from c# code

I am sending emails to users to confirm their email account upon registration using smtp.zoho.com. these emails are intermittently failing with the following error:

System.Net.WebException: The remote name could not be resolved: 'smtp.zoho.com'

any ideas what could be the cause? Is there an alternative to this smtp address that i can use?

thanks,