When you look at your list of Web Users who are allowed to log into your Andar web site, do you see a lot of rows (for employee donors) with User IDs that have 1-digit numbers on the end of them?
Typically, that happens whenever a web user record is created, and there's already a web user record that exists with the same User ID. This naming convention occurs because there's a rule that says no two user IDs can be the same — all User IDs have to be unique.
So, if there was already a Web User record with User ID = JohnDoe@org.com, and then someone instructs Andar to create new Web User records by using the e-mail address as the ID, Andar would try to use JohnDoe@org.com, but it would see that 'JohnDoe@org.com' is already used. As a result, Andar adds a number to the end of it, creating in a new web user, 'JohnDoe@org.com1'.