Set dynamic reply-to in Mail component

If you're using a traditional mail server if you let send mail on behalf of others, for it sends the mail to the mail unit, "From", which no matter what server coreo have, always will be sent as if it were put the mail in the From. 
If you use the Google SMTP for example, security will not let you do this you have to do is to allow this as sending mail and gmail account, which does not serve you if you want to do it dynamically. 

regards

So you should only use it as a parameter in the mail template. We carry replacements notifications from database and passing several parameters using java libraries with json, which had only the value of the parameter and reads a notification. 

Or just what you can do is contact a template: 

href="mailto:$$mailReplyto$$">$$mailReplyto$$</a>

And pass the email in the header