AspSQLProvider

As far as i know the original SqlMembershipProvider also does not check for unique e-mail addresses in the UpdateUser method.

Should we implement this as optional feature?

The default membership behavior is not to check for unique emails while updating a user.

If i implement a custom exception that is thrown when updating a user it maybe that the caller of UpdateUser() is not aware of this exception.

So if you want to validate unique email addresses try the following code:

1 var user = myMembershipUserObject;
2 
3 if (!string.IsNullOrEmpty(Membership.GetUserNameByEmail(user.Email)))
4     throw new Exception("Duplicate email address...");
5 
6 Membersip.IpdateUser(user);

yeah, the default behavior is not to check for unique email address, but
there is an option RequiresUniqueEmail in MembershipProvider
and if this property is set to true UpdateUser throws an exception
if the email address is not unique

Hello,

you're right.

I get the following exception when calling Membership.UpdateUser() when the e-mail address already exists:

English:

System.Configuration.Provider.ProviderException was unhandled by user code
  Message="The E-mail supplied is invalid." 
  Source="System.Web" 
  StackTrace:
       at System.Web.Security.SqlMembershipProvider.UpdateUser(MembershipUser user)
       at System.Web.Security.MembershipUser.Update()
       at System.Web.Security.Membership.UpdateUser(MembershipUser user)
  InnerException: 

German:

System.Configuration.Provider.ProviderException was unhandled by user code
  Message="Die angegebene E-Mail-Adresse ist ungültig." 
  Source="System.Web" 
  StackTrace:
       bei System.Web.Security.SqlMembershipProvider.UpdateUser(MembershipUser user)
       bei System.Web.Security.MembershipUser.Update()
       bei System.Web.Security.Membership.UpdateUser(MembershipUser user)
  InnerException:

So, ticket is reopend. I'll fix this asap.

Thanks.