[rt-users] External users unable to create tickets since ExternalAuth activated

[Nicôle Layne-Balram]

Since implementing external auth (LDAP option), RT works as expected for users 
within AD, but I've just realized that external users are unable to create 
tickets, even with the appropriate "Everybody" permissions set via the web 
interface (globally as well as queue-specific).

Error within logs: 
*timestamp* RT RT: RT::Authen::ExternalAuth::CanonicalizeUserInfo returning 
Comments: Autocreated on ticket submission, Disabled: 0, EmailAddress: 
y...@hotmail.com, Name: y...@hotmail.com, Password: , Privileged: 0, RealName: 
Jane Doe 
(/opt/rt3/local/plugins/RT-Authen-ExternalAuth/lib/RT/Authen/ExternalAuth.pm:536)
 
Jan 10 21:21:58 RT RT: Couldn't load user 'y...@hotmail.com'.giving up 
(/opt/rt3/bin/../lib/RT/Interface/Email.pm:947)

RT_SiteConfig.pm:
Set($rtname , "xxx.com");
Set($Organization , "xxx.com");
Set($Timezone , 'US/Eastern');
Set($DatabaseType , 'mysql');
Set($DatabaseHost   , 'localhost');
Set($DatabaseRTHost , 'localhost');
Set($DatabasePort , '');
Set($DatabaseUser , 'rt');
Set($DatabasePassword , 'xyz');
Set($OwnerEmail , 'root');
Set($RTAddressRegexp , '([a-z]+)\...@rt\.xxx\.com$');
Set($ValidateUserEmailAddresses, 1);
Set($CorrespondAddress , 'no-re...@rt.xxx.com');
Set($CommentAddress , 'no-reply-comm...@rt.xxx.com');
Set( $WebDomain, 'rt.xxx.com' );
Set($WebPath, "");
Set($CanonicalizeRedirectURLs, 1);
Set($LogToSyslog , 'info');
Set($UnsafeEmailCommands,1);
Set($LogToSyslog, "debug");
Set($AutoCreateNonExternalUsers, 1);
Set($AutoCreate, {Privileged => 1});
Set(@Plugins,qw(RT::FM RT::Extension::QueueDeactivatedScrips 
RT::Extension::MobileUI RT::Authen::ExternalAuth));
require "/opt/rt3/local/plugins/RT-Authen-ExternalAuth/etc/My_RT_SiteConfig.pm";

1;

External User gets two returned e-mails from no-re...@rt.xxx.com:
RT could not load a valid user, and RT's configuration does not allow for the 
creation of a new user for your email.
User 'y...@hotmail.com' could not be loaded in the mail gateway

Any help and suggestions would be greatly appreciated.

Thanks,
Nicôle