Support for Outlook .msg format in Portable Thunderbird ??

I want to save e-mails, sent from MS Outlook to Portable Thunderbird, to disk in the Outlook .msg file format

E-mails sent from MS Outlook to Portable Thunderbird (PTB 2.0.0.17) that I want to save to disk give me the option to do that in .eml , .htm , .txt file formats.
I would like to do it in the Outlook .msg format. I have not been able to find a solution on the various forums and Q&A's.
Does PTB support this?? Where can I find it?? I am fairly familiar with PTB's Tools Options part, but do not see it there.
I have been using PTB to great satisfaction for about 4 years now. This would make the program even more useful to me.
Any answer is appreciated.
Jacoppy