There is a possibly that they already have your "personal" information. The owner of RBS is a scheduler for another MSC. Not that the two MSCs would share information but how else do you think RBS received your email address. It may have been courtesy for a Shopper who shops for one MSC, may want to shop for another
When you fill out profiles, particularly on some job posting sites, there will be a question asking for permission to share your information, and you may have selected this. Some ICA agreements may also include this permission. A third option might be that some schedulers work for multiple companies.