Ian Eiloart wrote:
>> The "headers_remove = User-Agent" line is something entirely different
>> that tends to help. You'll find many references on the web to hotmail
>> blocking certain messages that contain Thunderbird in the User-Agent
>> header, but allowing through messages that are exactly the same, but
>> without the User-Agent header. I tested this myself a while back and it
>> was true.
>
> Why would an MUA add a "User-Agent" header? It's an HTTP or net-news
> header, not a mail header.
> <http://www.iana.org/assignments/message-headers/perm-headers.html>
> Arguably, Microsoft are doing the right thing by punishing clients for
> using non-standard headers.
Non-standard headers? You can add *any* arbitrarily named header you
want to an email. At least Thunderbird and Mutt both use "User-Agent".
I've not tested other MUAs. Microsoft aren't, "doing the right thing,"
or anything even close to sensible by scoring so harshly on this header.
> Perhaps the sensible thing to do is to replace the User-Agent header with
> an X-mailer: header
>
> Or, perhaps someone should register user-agent as a mail header.
> <http://tools.ietf.org/html/rfc3864> says how, and says that part of the
> point is "encouraging convergence of header field name usage across
> multiple applications and protocols"
Or perhaps Microsoft should drop SmartScreen and use a decent filtering
technology.
Mike
