Messaging a person not in the system.

Marie has asked me to message her through eccie but she isn’t in the system. I tried the tel. # with no luck. Am I just showing my ignorance in use of technology?
I haven't tried to contact her on here, but here is her profile if you want to give it a shot:
https://www.eccie.net/member.php?u=500836
Thank you, it finally did work out.
Awesome- I hope you have a great time with her!