this is correct, but in the iRedMail.tips file there is no mention of this username format, nor is there mention of the username needing to be put in this format to work, for a newbie to PHPldapadmin it can be vexing as during the iRedmail setup there is a place to input the ldap admin user, but it implies that the username is just :vmailadmin or :vmail, the only way I discovered how to login was pouring over the .conf files for ldap and trying everything related to a username I could find.  A request I would make is that during the setup process while setting up the phpldap admin user it would specify that the username format has to be in ldap format of cn=vmailadmin,dc=$domain,dc=com