User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; rv:1.7.3) Gecko/20040913 Firefox/0.10.1 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; rv:1.7.3) Gecko/20040913 Firefox/0.10.1 If the sender of an e-mail is i.e. "hans glück" and you press "reply" thunderbird 0.8 will try to replay to "hans" and to "Glück" as to two separate accounts. Reproducible: Always Steps to Reproduce: 1.Create an account with the described characters 2.Send an e-mail 3.Reply to it Actual Results: see above It will try to find "hans" as an e-mail account which usually still contains the corect address and "Glück" which contains no address at all. May be you will get a bounce message. Expected Results: should reply to "hans glück" as a unique address

Is the original address actually "Hans Glück" or is it "Glück, Hans"? The latter is a known problem; see bug 254519. If you are not convinced that bug is the same as this, please find (or create) a sample message that shows the problem, save it as a .EML file, and attach it to this bug using the Create New Attachment link above.

From the attachment: ------------------- Example of a person: From: =?iso-8859-1?B?Ikf8bfxzbPwsIENhbmFuIg==?= her name is Canan Gümüslü, message sent 28 April 2004, is diplayed correctly From: =?iso-8859-1?B?R/xt/HNs/CwgQ2FuYW4=?= the same person, message sent 09 Sept 2004, is displayed as mentioned above. ------------------- That's the clue needed. The first From: decodes as "Gümüslü, Canan" with quote marks The second From: decodes as Gümüslü, Canan without quote marks The first presumably was from a message created by Mozilla or TB; that's a known issue with its RFC 2047 encoding -- the quotes shouldn't be necessary. But the duplicate is about how, *without* quotes, the name string is incorrectly treated as two separate addresses. Then bug 156588 is about how "two" addresses on the From line are shown differently in the thread pane and in the envelope panel. *** This bug has been marked as a duplicate of 254519 ***