This free software was originally produced by Oivmail, Inc. The software lies within Communication Tools, more precisely E-mail Tools. The most popular version among the program users is 0.5. OIVMailer.exe is the most common filename for this program's installer.
From the developer:
OIV Mailer is an application to view, send and receive regular email and OIV Stamped Mail. It has all the basic features of mail clients like “Outlook Express”, “Outlook”, “Thunderbird” and “Eudora” and adds all the features of OIV Mail. In particular OIV Mailer manages folders to give you a completely clean inbox. The main window consists of Title bar, Menu bar, hot button bar, three resizable panes and a status bar.
You may want to check out more software, such as AA Mail Server, Live Mail Contacts Export to Outlook or Importing Live Mail Contacts into Outlook, which might be similar to OIV Mailer.