ripl, the problem you complained about with large .mbox files is solved! MBox Viewer is a very nice program! The author, Enea Mansutti, has updated it (January 21, 2015) to work with very large .mbox files. It now works well for me on 64-bit Windows 7 to read a 14.9 GB .mbox file containing my saved gmail archive (which I downloaded from Google Takeout). Of course, the initial load of a 14.9 GB .mbox file takes a long time, but that's unavoidable, because the .mbox file format has no index. So any program which reads it has to read the entire file, to build an in-memory index. Enea also enhanced the main display, to show "to" addresses (instead of just "from" addresses), and he added an "attachment" indicator. He also apparently incorporated some performance enhancements. He also enhanced the search function considerably. The search can now still search entire message bodies as before (i.e., search the entire .mbox file, which is slow!), but you now also have the option of searching just the message headers, which are kept in in memory, so that's fast! Also, you can constrain the search to include just a desired range of dates, which is very useful. Enea made all these improvements just because I emailed him and told him that the old version didn't work on my giant .mbox file, and asked him whether there was an updated version. What a nice guy!
It's unpossible to open large MBOX files, it shows empty folder, no error message etc. It can not show correctly spec.characters (Czech), it can not to find Czech words in messages. There is not a possibility to sort messages (date, from...)
Love the utility. It missed out on one star as it is missing Open File option, it only has Open Folder. This is missing both in GUI & commandline. I was intending to use it an an external viewer for WinSCP where I'd need a command invocation something like [utility fullpath] <winscp temporary filename>.
The product allows you to view and MBOX in a decently formatted fashion. The only suggestion would be to allow EXPORTS of Selected Email or ALL EMAIL to TXT or PRINT directly a particular Email. But in-lieu of importing into Thunderbird, this is a nice quick solution.. THANKS!