Redmine

I have Redmine set up for my shop and everything is running great, love it to death. But now other shops are seeing our system and want to be added to our system for their own usage. I've managed to figure out importing separate email accounts into their prospective projects and trackers, but I don't know how to change the "Sent from" aspect. I don't want to confuse the users with thinking our shop handles all the mail from all the shops being added as separate projects.

Only concept I've though of thus far is making a new database and have a different entry in the configuration.yml for them. But then I would have to manage 4+ databases doing the same thing and just sounds inefficient. So I'm just wondering if anybody knows of a working plugin for 2.5.1 or some other work around.

Thanks in advance.

Environment:

  Redmine version                2.5.1.stable
  Ruby version                   1.9.3-p545 (2014-02-24) [i686-linux]
  Rails version                  3.2.17
  Environment                    production
  Database adapter               Mysql2
SCM:
  Subversion                     1.6.11
  Git                            1.7.1
  Filesystem
Redmine plugins:
  clipboard_image_paste          1.8
  projects_tree_view             0.0.8
  redmine_contacts               3.2.17
  redmine_contacts_invoices      3.1.4
  redmine_custom_workflows       0.0.4
  redmine_improved_searchbox     0.0.3
  redmine_knowledgebase          3.0.4
  redmine_logs                   0.0.5
  redmine_monitoring_controlling 0.1.1
  redmine_people                 0.1.8
  redmine_zenedit                0.0.2
  unread_issues                  0.0.1