SME Server talk:Documentation:Administration Manual:Chapter9

I suppose it will be great to have also one note into Practical usage guidelines about removing the default SME server behaviour to auto create pseudonyms

I propose:

In this scenario (multiple domains) You probably will not need any more the auto creation of pseudonyms 
To achieve this comment with an # at beginning the line 793 into /usr/lib/perl5/site_perl/esmith/FormMagick/Panel/useraccounts.pm

the line should be like

#    $accountdb->create_user_auto_pseudonyms($acctName);