[Users] mangling URL?

[Dave Howorth]

I get mails from my local planning authority that include links to
particular planning applications. When I click on those links, the
result in Firefox is broken (rewritten). Is it claws or firefox doing
this?

The mails are of type

Mime-Version: 1.0
Content-Type: text/html; charset=us-ascii

The part of the URL that gets broken is the query parameters:

...?caseType=Application&keyVal=...

in the message source and in claw's display becomes

...?caseType=Application\\&keyVal=... 

in Firefox's URL bar.

Any ideas as to what's going on and how to fix it?

(and yes, I know they should be sending a text part as well and I
appreciate claws is doing me a favour by showing anything at all.)

Cheers, Dave

PS  I'd rather not post the whole message but will send it privately if
requested.