NOTE: this is low priority.
In the MBSE manual, in describing mbmsg's "post" command, the manual states:
"(from), (to), and (subj) need to be enclosed in double quotes or use an underscore in the place of a space if the fields contain spaces."
I have just verified that using underscores does not work. Using double quotes does work.
Diff:
Note that format for mbmsg is :
po post <from> <to> <#> <subj> <file> <flavor> Post file in msg area # </flavor></file></subj></to></from>