ArtStation artists have the ability to add various mechanisms for being contacted such as a public-facing email address, enabling the "Message" button or providing links to other sites where they can be further contacted.
Check the About section on the artist's profile.
If a public email address is listed, you can send them a message directly from your email client.
Message button
Click the green Message button on the artist's profile.
Choose between sending a General or Business-related inquiry.
Note: You must be signed in to your ArtStation account to send messages.
Social sites
Look for external links on the artist's profile to platforms such as their personal website, LinkedIn, or Facebook.
If no contact information is provided
If an artist hasn't provided contact details, it means they prefer not to be contacted.
ArtStation Support cannot share private contact details or put you in touch with an artist due to privacy policies.