How to edit mailfrom in joomla?

Mostly of the developer encountered problem in editing the default mailfrom in joomla
but there are many solution on this.
First Solution:
1. Go to site_url/
2. Edit the configuration.php
3.Find:

 var $mailfrom

4.Then Edit to the desired mail from

Second Solution:
1. Go to admin/global Configuration/Server
2. Edit Mail From Field.

3rd Solution:
1.Go to PHPmyadmin
2.databasename/jos_vm_vendor
3. Search the old mailfrom
4. Edit to the new one

How to display dynamically the category name in frontend,admin and also in email sent in virtuemart in the desired position?

Mostly in virtuemart display category name in the admin but you cannot control where you want to display.