If we detect suspicious sign-in attempts on your account, we’ll email you a sign-in link the next time you access your account. This is a proactive security measure that ensures you're the only one accessing your Dropbox account.
What if I didn't get an email with a link?
If you didn't receive an email from us, first check your spam filter. You may need to add firstname.lastname@example.org to your contacts.
If you're still unable to access your account, contact Dropbox Support.