Downloading ImportServer 2.0.2 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. This Mac application is an intellectual property of Weird Kid Software. ImportServer for Mac lies within Communication Tools, more precisely E-mail. The most popular version among the application users is 2.0.
From the developer:
ImportServer helps you import email into email applications. Specifically, the ImportServer acts like an email server that holds all your old email, ready to be downloaded into your new email application. Use ImportServer when your new email application does not provide an option to import your old email.
You may want to check out more Mac applications, such as Zimbra Toaster, PageSender or EEAO, which might be similar to ImportServer.