Yes, they sure do have a motive - to send spam via a 3rd party service. Like in this case (GitLab) - create a fake "issue" with spammy links in it and then "no

Yes, they sure do have a motive - to send spam via a 3rd party service. Like in this case (GitLab) - create a fake "issue" with spammy links in it and then "notify" thousands of users. In our case - we are a helpdesk ticketing app, so bad actors sign up for a trial, then add "users" to their account and then, say, create "tickets" on users' behalf (customizing the email template by inserting spammy links).