[FX.php List] off topic: "share this site with a friend" best practice

[Alex Gates]

Hi everyone - 
I apologize for the off-topic message - If anyone has a minute to share
an opinion, I would really appreciate it.

I'm putting together a "share this site with a friend" page and I am
interested in hearing other's experiences with this.
I want to employ the best method and ensure my mail server wont be
flagged as a spam server.

I've seen some "share this site with a friend" pages that allow the user
to enter their name and email address.  Then, they have a text area
where they enter email addresses seperated by commas - and finally, some
pre-written text in a text area.

I imagine the script takes the user's name and uses it as the name field
of the email address.  I also imagine that they use they use the user's
email address as the specified reply-to address.

Is this a good method?  I would use the SwiftMailer class and a SMTP
mail server to do this, but I'm not sure if it is a good idea or not!

Is this method vulnerable to exploitations?

Would it be advisable to use CAPTCHA on bottom of this form?


The other idea is to simply ask for the user's name and their friend's
email address - then send the email (un-modifiable) to their friend's
email address from our company's email address and use a subject line
like "Alex Gates wanted to share this website with you" or something - 

I'm not sure if one method is "safer" than the other method - or if I am
thinking about this completely incorrectly.  

Bottom line - I don't want to be vulnerable to exploitations that could
lead our mail server to be flagged in the spam databases.

Any advice, comments, or experiences would be very helpful.

Thanks!

Alex