Downloading IlohaMail 0.8 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. The application lies within Communication Tools, more precisely E-mail. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
IlohaMail (pronounced: e-lo-ha-mail) is a light weight yet full featured multilingual webmail program that is easy to use and install. It runs on a stock build of PHP, and does not require databases (although database support is available) or the IMAP library (it is powered by a custom IMAP/POP3 library).
You may want to check out more Mac applications, such as Installer OS X El Capitan, which might be similar to IlohaMail.