Thanks shannon,
The encoding on the machine is UTF-8 and it did not change. I saved the message with Mozilla Thunderbird just after receiving it from my server. Then I read the message using FIleReader (UTF-8 encoding again) only to make sure that the question marks visible in the message are really question marks, not some characters unrecognized by Thunderbird. I'm pretty confident that the message is already sent with question marks instead of UTF characters. What's quite surprising is that on my other machines JavaMail uses quoted-printable transfer encoding and here it uses 7bit encoding (to send the same message) which I thought should only be used with US-ASCII charset.
I'll try to investigate this further..
Thanks for your help
Olaf Tomczak
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