Hello,
We have a form that populates to a Sheet 1.  The employees enter general information, except for their employee number.  We have Sheet 2 that has the employee# and so we are able to pull in the employee # into Sheet 1 using Match.  
=IFERROR(INDEX({Master Non-BVS User ID}, MATCH(Email@row, {Master Non-BVS Email}, 0)), "")
This works perfectly as long as we just have the email address in those columns.  As we start having more contacts in SS we are running into a problem were it is not recognizing the information due to the column having the full contact information (Name and Email) vs just the email address.  I have been manually going to into the contact at the cell level and removing the Name for the formula to work.
After thinking about it I was thinking is a Index Match Contains formula would work and since the email would get a partial match.  Looking online I found Index Collect Contains, however it isn't returning any value so it isn't recognizing the email from the contact.   
=IFERROR(INDEX(COLLECT({Master Non-BVS User ID}, {Master Non-BVS Email}, CONTAINS(Email@row, @cell)), 1), "")
Thank you!