Sorry it took me so long to get back to this...  Like I said, SMTP tests, new user registrations, I get those emails... But when a new user tries to register, it gives me that error which is posted in the beginning of this discussion. They dont' stay logged in... and have to click login again, and enter their username and password and yes, it saved it..  Also, a contact form that I install on just about every website I build isn't working.. it isn't sending emails.

Here is the error:

ModuleId: -1
ModuleDefId: -1
FriendlyName: User Registration
ModuleControlSource: DesktopModules/Admin/Security/ManageUsers.ascx
AssemblyVersion: 5.5.0
PortalID: 0
PortalName: The Cartridge Shoppe
UserID: -1
UserName:
ActiveTabID: 40
ActiveTabName: Home
RawURL: /register.aspx?returnurl=http%3a%2f%2fmywebsite.com%2fcontact.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer: http://mywebsite.com/register.aspx?returnurl=http%3a%2f%mywebsite.com%2fcontact.aspx
UserAgent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_4; en-us) AppleWebKit/533.16 (KHTML, like Gecko) Version/5.0 Safari/533.16
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: d3c64e0e-20ab-4e11-b407-1e811c823bf6
InnerException: Mailbox unavailable. The server response was: <myemail@gmail.com> No such user here
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Net.Mail.SmtpTransport.SendMail
StackTrace:
Message: DotNetNuke.Services.Exceptions.ModuleLoadException: Mailbox unavailable. The server response was: <myemail@gmail.com> No such user here ---> System.Net.Mail.SmtpFailedRecipientException: Mailbox unavailable. The server response was: <myemail@gmail.com> No such user here at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, SmtpFailedRecipientException& exception) at System.Net.Mail.SmtpClient.Send(MailMessage message) at DotNetNuke.Services.Mail.Mail.SendEmail(String fromAddress, String senderAddress, String toAddress, String subject, String body) at DotNetNuke.Services.Mail.Mail.SendMail(UserInfo user, MessageType msgType, PortalSettings settings) at DotNetNuke.Entities.Modules.UserModuleBase.CompleteUserCreation(UserCreateStatus createStatus, UserInfo newUser, Boolean notify, Boolean register) at DotNetNuke.Modules.Admin.Users.ManageUsers.UserCreateCompleted(Object sender, UserCreatedEventArgs e) --- End of inner exception stack trace ---
Source:
Server Name: WEB26

Hi,
I am using Portal version 5.04.02
All email settings in the menu on the host've done. the test email successfully done.
But when the user wants to register a message (("An error has occurred.
Error: User Registration is currently unavailable. ")) is issued.
Of course, users will develop.
Please help me.