I have an email database with a couple of thousand members and a twitter account with a couple of thousand followers. Many of them are in both lists for sure.
For the purpose of segmenting the email database, it would be great if I could know who from the email database has a Twitter account.
It's not important to know their Twitter user names or id's, but if that comes as an extra, even better.
Twitter API allows a lot of queries, but I didn't find one that allows search users by email address.