I believe I’ve found a bug in the /api/v2/search/contacts route. It throws an error stating an email address in the query is invalid:
I’ve traced the issue down to + character in email addresses. e.g. josh+test@geemail.com. We frequently use the + sign in our email addresses as a way to create test accounts and not create other real email addresses. If I remove the + from the email the search call works normally.
A + sign in the left side of an email address should be considered valid by your API.
I also noticed a related issue in this forum: Email validation does not follow RFC Specs