I am using a Godaddy hosting account with their smtp relay account, Anonymous authentication with user and password blank.   Submittedit to the host admin 'test'  returns "Email sent successfully' and we have received email traffic from other processes such as user account update notifcation.

The following is the log entry for the exception

AssemblyVersion: 04.03.03
PortalID: 0
PortalName: Blah Blah
UserID: 10
UserName: Super User
ActiveTabID: 36
ActiveTabName: Home
RawURL: /Store/Home/tabid/36/ctl/Edit/mid/445/ItemID/4/Default.aspx
AbsoluteURL: /Store/Default.aspx
AbsoluteURLReferrer: http://www.blahblah.com/Store/Home/tabid/36/ctl/Edit/mid/445/ItemID/4/Default.aspx
UserAgent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.1; WinFX RunTime 3.0.50727)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: 844b1e48-61ad-4073-bb56-4ab188f36ef8
InnerException: The SMTP host was not specified.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Net.Mail.SmtpClient.CheckHostAndPort
StackTrace:
Message: System.InvalidOperationException: The SMTP host was not specified. at System.Net.Mail.SmtpClient.CheckHostAndPort() at System.Net.Mail.SmtpClient.Send(MailMessage message) at DotNetNuke.Services.Mail.Mail.SendMail(String MailFrom, String MailTo, String Cc, String Bcc, MailPriority Priority, String Subject, Mailformat Bodyformat, Encoding BodyEncoding, String Body, String Attachment, String SMTPServer, String SMTPAuthentication, String SMTPUsername, String SMTPPassword)
Source: