Resolve ambiguous names by using EWS

[nvPhong321]

I have a question about "Resolve ambiguous names by using EWS :" I have a list of usernames "use-r1@gmail.com, #user2@gmail.com, 2user@gmail.com" and I'm searching username by but I encountered the following cases :

• when I input "r" the results return all usernames
• when I input "#" the result is "#user2@gmail.com"
• when i input "-r" it returns an error is "ErrorNameResolutionNoResults"
• finally when I input number "2" it returns only "2user@gmail.com" and without "#user2@gmail.com"

this is my code : `<ResolveNames xmlns="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types" ReturnFullContactData="true">

keysearch

`

So I have some questions :

• The searching will depend on which part of the username? the first character, or match with
• Is there any way to unify the search, such as searching based on the first character of the username?