More encoded subject woes

[Nick Smith]

On 5/19/06, Nick Smith <nick.smith67 at googlemail.com> wrote:
> Hi,
>
> MS 4.54-2 / Postfix 2.10
>
> I've got more trouble with encoded subject headers being "mishandled"
> from a recipient's point of view. The issue occurs when, for whatever
> reason, MIME-Tools is unable to decode an encoded subject properly -
> this example is UTF-8, but I don't know if it may affect other
> encoding types too
>
> =?UTF-8?B?5oOF5aCx6YCj57Wh56WoIC0gVVNHcumVt+WQiOitsOW+heOBoSA=?==?
> UTF-8?B?LSDnrKzvvJTvvJjlm57lhajml6XmnKwgLSDlsZXnpLrkvJrjga7lh7rlsZU=?=
>
> If you feed that string to MIME::WordDecoder::unmime it returns:
>
> ????? - USGr????? - ??????? - ??????
>
> I have absolutely no idea why this happens - whether it's a bug or
> expected behaviour on the part of MIME-Tools, but I assume that each
> question mark represents a multi-byte (Japanese in this case)
> character that it was not possible to decode
>
> Drop the same string into an Outlook message and send it via SMTP
> (making sure that it bypasses MailScanner), and when it arrives it
> should show a bunch of Japanese characters. The recipients are
> understandably not happy that the subject of their email when it shows
> up has been replaced by a bunch of question marks
>
> I've worked around this problem with a patch against Postfix.pm
> (attached), but I'm less than comfortable with it. Basically what it
> does is to unmime into a temporary holding string instead of the
> $message structure and then take a look at the results of its
> handiwork. If it sees more than an arbitrary number of consecutive ?'s
> (I picked more than 3 as a reasonable number), it assumes that the
> unmime was unsuccessful and allows the original encoded subject to
> pass. Otherwise it assumes decode success and fills the
> message->{subject} structure with the unmime result
>
> The first problem is that the ???? test is far from foolproof -
> there's loads of scope for false +ves and false -ves. The second
> problem is I'm not sure what issues this might cause if MS has to
> alter the subject later. I'm not altering any subjects at all so it
> wouldn't be a worry on my system but...
>
> Clearly I'm working with Postfix here, but this affects other MTA's
> too. Equally clearly the proper answer is to figure out what's up with
> MIME-Tools, but I'm afraid that's way beyond my capabilities :(
>
> Thoughts appreciated
>
> Thanks
>
> Nick
>
>
>

Please ignore all of this - I think I've been fed old news by the
group that reported this to me as an issue

I'm pretty certain that their problem was actually the "Postfix
truncates multi-line subject" thing that Julian already fixed for me,
and that when they said they were still having the issue after
re-testing they were mistaken

I am working on the assumption that the ???? output from the unmime
function is just an ASCII representation but it was plenty enough to
confuse me :(

Sorry for the false alarm

Thanks

Nick