This is what I got;
You requested a magic link for logging in to vanhack.slack.com. Unfortunately, this email address isn't currently associated with that team.
We also searched for Slack teams you've already joined or are allowed to join, using email@example.com.
Unfortunately, we couldn't find any teams for that address.
If you're looking for a specific team, you can try contacting your Team Administrator for an invitation. You can also try a different email, or forge ahead and create a new team!
Please let us know if you have any other questions or feedback. And thanks for using Slack!
The team at Slack