How can I specify the charset for the outgoing message?
The plug-in is choosing the encoding for the message automatically, based on the characters present at the message. For example, if the plug-in chooses the ‘windows-1250’ encoding, this should mean that your message contains character(s), which belong to one of the languages designated at: http://en.wikipedia.org/wiki/Windows-1250 So, in order to get a message with ‘Western’ or ‘US’ characters encoding, you should use (only) the corresponding characters in your message. Please notice, that if you use a combination of characters in your message, which can not be put in 8 bit encoding, the plug-in will use the Unicode encoding for this message.