Many users complained from my messages over this mailing list (and other
lists) because I'm sending only HTML formatted messages although I
configured my e-mail client to send PlainText & HTML format.
Recently (since weeks ago) I discovered the cause of this problem
is an addon I use in Thunderbird for supporting multi-layouts formats
(Right To Left / Left To Right).
I'm very sorry for disturbing you.
Muhammad Bashir Al-Noimi