If people in your email contacts are receiving invitations from you, it's because you previously imported an address book and the system sent invites on your behalf. You can't unsend invitations that have already gone out, but you can deactivate your address book to stop any future ones.
Why did my contacts get invited?
When you import an address book, Alignable walks you through two steps: first, connecting with existing members, then inviting non-members to join. If you clicked "Add All" on the second screen, the system sent an invitation to everyone on that list.
How to stop future invitations
To deactivate your address book and prevent any additional invitations from going out, submit the Request to Deactivate My Address Book form. Once submitted, your address book will be unsynced and Alignable will no longer be able to contact anyone in it.
What happens after deactivation?
What about invitations already sent? They stay in the recipient's inbox. If the recipient has an Alignable profile, it shows up as a connection request. If they don't, it's an invitation to join.
What happens to connections I made through those invites? Those connections stay active. If you want to remove any of them, you can do so from your connections list.
Can I see exactly who was invited? There's no way to pull a precise list of who received invitations. You can check your Accounts Page to see which address book was synced — everyone in that address book is who the system attempted to invite (though Alignable filters out non-business addresses before sending).