InfoPath Dev

All, I have InfoPath form which process data of List 'Risk' which saves Risk details. In this List a Column as Business owner is present which is Person or Group type. I received a requirement to add Dropdown and add fixed list of users for this field. So i created a new list as 'User' where i have 2 columns i.e. User and Email, which saves username and his email id respectively. I have added this as 'Field3' as dropdown list on InfoPath form of Risk List. I can see all Usernames from 'User' List in this dropdown list. I have added a Rule which copies dropdown value from Field3 of User list to Business owner column of Risk List. Issue is when there are 2 email id for someone in Org, then it gives error when i select value in dropdown and it copies name in Business owner field (Person or Group type). I want that when i select person name in Field3 Dropdown email id of that value should be displayed on Business Owner column. i need to understand how to set filter condition so i can retrive correct value. Every time it fetch value from 1st row of list. Attached is a screen shot

Just added an example to make question simple. e.g. I have List called Risk which have below columns List Risk - Column A, B, C, D (Suppose D column is of Type Person or Group). InfoPath form works well to accept new records in List 'Risk'. Now i have new requirement to accept values of Column D using a Dropdown List. It was not possible to convert Person or Group type column as Dowpdown in Infopath form. So created another List 'User' which have below columns List User - Column User, Email In InfoPath form created data connection for List User and added a Dropdown for column 'User' from 'User' list. Then added a rule 'Set Fields value' of column 'D' when a value is selected in Dropdown of 'User' column on InfoPath form. It works well, however when an user have 2 id's in same organization then it gives an error. To solve this i want to use column 'Email' of 'User' List for the above rule. so at the end what i want is when User selects a value in Dropdown of column 'User' the rule should retrieve related 'Email' column's value from 'User' List. Please suggest how to achieve it.

All, :) somehow i have resolved that issue by correcting my filter criteria. It is like below While setting Fields value in Value field selected 'Email of User List' Then added Filter where Field3 of Risk List = UserName of Email List) It worked well. However now i face new problem. So here i select name from Dropdown List of User List and based on selected name, email id of corresponding person is selected from user and displayed in Column D of Risk List. However when i click Submit, it gives below error. however when i select the person name manually in column D it works well.

You are setting a people picker? I think you need to set both the account id and the display name.

Thank you, Is it possible to set both account id and Display name through single rule? pls let me know how to set it?

Thank you, The issue is resolved now. While setting Rule to Set field's value, It is set as below. Field - Account ID (of Column D) Value - Account ID of column Email from User List where Filter is added as (Field3 i.e. Dropdown list value = Account ID of Display Name of User Column from User List) I know its difficult to explain it easily however your suggest above has helped to resolve it.