I set the message size limit to 100K in Thunderbird but could not download the full message with the download link. I believe it is a common setting and the loading the truncated message should work in general. Probably it has something to do with using SSL with POP3 though I could not verify it, my company's email server only allows SSL for POP3. When I click the download link, there is no respeonse of any kind. However it works fine when using Mozilla email client.
Thanks,
-- Yi