On 10/02/2010 00:04, Ted Mittelstaedt wrote: >>> Thunderbird only displays the SECOND subject line. >> >> So Thunderbird displays the last Subject line header it comes across. Is >> that incorrect behaviour for an MUA? > > I think it is. Setting aside the question of whether they are supposed > to be there or not, the purpose of an MUA is to make it easier for > the user to interact with a mail message. Multiple Subject: lines > can contain multiple amounts of information, and only displaying the > last Subject line is denying the user information that they are > supposed to be able to see see. > > A deeper question is do all parts of t-bird treat this equally. If > the filtering in t-bird reacts to both Subject line contents then > this definitely is a bug. A user might have a filter saying > "delete all mail with viagrera in its subject line except mail > that has "fred" in it's subject line. The spammer sends a message > with the first subject line having viagrera in it, the second > subject line having fred in it, and the message is not deleted - but > the display only shows viagrea.
You could probably have tested that yourself in the time it took you to write that paragraph. >> Is it valid for an email to have >> more than one Subject line? > > I do not think this defined anywhere. But I won't swear to it. I > think it's not particularly valid, however because the results are > undefined. Did you check? I would bet that it is defined... I just took a quick gander at rfc2822 and it states: "No multiple occurrences of fields (except resent and received).*" There might be other RFCs involved, but it looks to me from that as though it's only valid for an email to have one Subject header. It's understandable that an MUA might not display an invalidly formatted email correctly. >> Bring it up with Mozilla. >> > > Since this is a SA bug I think I will file it with Mozilla just > to have it in the database, but I would only argue for internal > consistency in t-bird. You've no reason to believe there is any internal inconsistency with regards to how Thunderbird treats Subject lines. And if it's true that it's not valid for an email to have more than one Subject line then this is not a Thunderbird bug, but still something that they may or may not wish to workaround. > At this point I am up against a wall. For starters this is an old ver > of sa, old sendmail, etc. This server is scheduled for re-gen soon and > there's no point in filing a bug on the old code. I will continue to > observe and once the server is re-gened then if it keeps happening then > I'll look into it further. I'll probably have to run the server for a > few hours with SA turned off to get the raw spam, not something that is > going to be very popular. Alternatively, configure your MTA to deliver an unmodified second copy of all incoming email to a separate maildir. -- Mike Cardwell : UK based IT Consultant, Perl developer, Linux admin Cardwell IT Ltd. : UK Company - http://cardwellit.com/ #06920226 Technical Blog : Tech Blog - https://secure.grepular.com/ Spamalyser : Spam Tool - http://spamalyser.com/
