On Sat, Sep 08, 2007 at 11:50:03 +0200, "joachim.backes@xxxxxxxxxxxxxx" <joachim.backes@xxxxxxxxxxxxxx> wrote: > > in the most emails, containing hyperlinks in the body, such hyperlinks > are marked by thunderbird. > > But in a few such emails, they are not marked. Can somebody explain > this? Especially, if I compose additional other emails to myself > containing these URL's, the are marked after I received them. It could be that you are mostly seeing message bodies that are text/html and that the exceptions are in text/plain. It also could be that the email client is doing pattern matching to pick out URLs in text/plain parts and some URLs aren't matching the pattern. Someone who knows more about Thunderbird might be able to give you a more definitive answer. However the above might be enough for you to go back and look at your example email messages and see if either case seems to account for what you are seeing.