I have been searching everywhere for an answer and can't find it.
I am working on a real estate website and when a user views a listing, I want them to be able to contact the listor (author) but I do not want to expose the authors email to the open web. Is there a way to allow the user to contact the author directly without having the email displayed?
Is there an extension or plugin etc that can do this?

Hi. You can do this by using the core contacts component. Just create a contact for each of your authors and then use a module or a plugin or even an extra field to link to the contact page. In case you have a lot of authors then it is probably better to search for a plugin since it will be difficult to create one contact for each author.

we will have a lot of users so the core contact option is not going to work. we would like to use the extra field LINK type to use mailto to open the users email client from the article. but i do not know what to put in the TEXT box and the URL box to make it work. we just get the domain.com/email@something.

This post will help you in creating the link.
www.w3schools.com/tags/tryit.asp?filename=tryhtml_link_mailto

You can always us HTML entities for the email.

Thanks Krigor,
But the problem is that the users will be creating their own articles and one of the extra fields for a property they are listing would be EMAIL. It is not going to be practical for them all to know and understand HTML so they can format that kind of link just to put in their email address so interested parties may contact them about a given property and we will have many differnet lister adding properties, all done from the front end.
I tried using the extra field LINK type but that adds 2 more fields for them to figure out when they create the property and 2 more that display in the fronted that are confusing to the readers. AND I could never get it to work. it always created the link as "domain.com\[email protected]" and that give a 404 error in the front end when clicked. It needs to bring up the users email client to create the message. If I could get that to work, I think I could hide the other fields.
With all of the things K2 does well, not having the ability to put a simple email type extra field, seems rather short sighted.
I have searched for some method of actually hacking a file to create the field but have come up empty. Right now this one thing may be a deal breaker in using K2 at all.

Quick note- after I wrote this I found an extension called EMAIL PROTECTOR that replaces the core Joomla cloaking plugin and works on all articles, including K2. If I use a standard text field and put an email address in - it is formatted as mailto: and then the address and brings up the email client.
So far it seems to work ok, but I need to test it on some kind of spambot to see.
www.nonumber.nl/extensions/emailprotector

Nice to hear that you sorted this out Gary.
You can create a link extrafield and specify the mailto://prefix.
I do not think that you need a new extrafield type for this.

Tried that- it does not work.
I enter "mailto: This email address is being protected from spambots. You need JavaScript enabled to view it." or
mailto:// someone@something,com

and when I save K2 changes it to http://mailto:[email protected] - adding the http://
I should not have to hack a file to get rid of that.
It is also not user friendly to tell users who may not know anything about html or what mailto means that they have to add that to their email address.
It is just disappointing that K2 does not include it out of the box.
As I read about v3.0 coming it, it is supposed to have an email filed and that will be good, but I cannot wait that long for it to be ready for a production site.
Anyway thanks again for your help!

I am reporting this is as an issue, it will be fixed in the DEV version. Thank you for your feedback.

u can use muliticontact eamail