We are using SDL 2013 sp1 with outbound email functionality.We recently implement a feature in our website where replying on any user comment we are sending the confirmation email to the comment owner.The email has some personalize information like comment and other data which is coming from database right now we are putting some placeholder in email page design and we are replacing this placeholder by manipulating EML file generated from CMS. Is there any way to replace this placeholder before Tridion generate EML file for each contact.
The main challenge with this is the context: when the Page is rendered for the confirmation e-mail, you don't know which Contact it is rending for. That information is only available when the Mailer service customizes the output for the Contact (i.e. replaces the placeholders with the actual data).
In short, until there is an event system available for Audience Manager, the current solution of modifying the e-mails before they are sent out is perfectly sensible.
EML file generated from CMS
You do know that it is your template that generates this file, right? Tridion executes a template that generates the eml files, and chances are, you are using placeholders in there too. I'd recommend looking into the documentation for Outbound Email, and finding out the code for your email templates so they can be adapted.
edit: words, tone & English