Litmus explicitly forbids any of our users from using Email Analytics for subscribers who have not opted-in. Our Terms of Service (which all users must agree to) state:
Under no circumstances may you use our tools in connection with the sending of Unsolicited Commercial Messages (spam). This includes our Email Analytics tools. You warrant that all your subscribers are opt-in and that every message you send has an appropriate mechanism for unsubscribing from your mailing list.
What to do if you've received spam
If you've received an email containing emltrk.com that you believe is unsolicited, please let us know immediately by forwarding the email to email@example.com. Our support team will investigate within 24 hours. If we discover the sender of the email is abusing the emltrk.com domain, we'll disable that user's account and blacklist them from using our products and services in future.
Have additional questions?
Our friendly support team can help recover a lost password, track down an unknown charge or send you a receipt. The best way to reach us is by emailing firstname.lastname@example.org or you can call +1 (866) 787-7030. We’re happy to help!