On Thursday 22 September 2011 12:31:40 Andrew Richards wrote: > On Thursday 22 September 2011 00:45:32 Timo Sirainen wrote: > > On 22.9.2011, at 1.59, Andrew Richards wrote: > > > I'm seeing a strange problem with some attachment filenames that are > > > UTF-8 encoded. The problem seems to be related to spaces and/or > > > unusual characters in filenames, like accented characters (or perhaps > > > just to filenames if UTF-8 encoded; I've not explored that fully). > > > > The problem is that the client sends it wrong: > > > Content-Type: application/octet-stream; > > > name==?UTF-8?B?dGhpc19mYWlscy50eHQ=?= > > > Content-Disposition: attachment; > > > filename==?UTF-8?B?dGhpc19mYWlscy50eHQ=?= > > > > These are both wrong. First of all they are illegal because they have = > > and > > ? characters, from RFC 2045: > > ...snip... > > > > Also from RFC 2047 (encoded-word is the =?UTF-8?...?= thing): > > > + An 'encoded-word' MUST NOT be used in parameter of a MIME > > > Content-Type or Content-Disposition field, or in any structured > > > field body except within a 'comment' or 'phrase'. > > > > ...snip... > > Anyway .. I'll check tomorrow if I can easily add code to workaround your > > problem. If it's just a minor change I'll do it. > > Wow - a very thorough response only 45 minutes after I'd posted the > question, and in your follow up message you've already provided a > suggested fix - a huge thank you! > > So in summary it's a "Garbage in -> Garbage out" issue... This also > explains why I'm only getting this issue with one client after a > Courier->Dovecot migration. I'll research which mail client program(s) are > generating the faulty messages for completeness for this thread. > > I expect to test the fix later today or tomorrow, I'll update the thread > accordingly when I've done so.
Firstly, my apologies - it's been a week before I've got back to this - I was making sense of another MIME issue which I thought might be related (it isn't), but I'll start a new thread for that. The fix works just fine. However... ...regarding the broken MIME fields: These look to occur in the form I noted for a single client program only, which on further investigation turns out to be an in-house[-written] mail program of my client, and therefore this problem is unlikely to bite other people: I've had permission to search the client's mailboxes for similar non-conforming emails and they only occur for this one in-house mail program. Summary: False alarm. However once again a huge thank-you to Timo for the patch to workaround this broken data. Best regards, Andrew.
