[Users] broken links in emails

[Dave Howorth]

Hello,

I receive some emails that include hypertext links. One of them doesn't
work. The link in the mail as received is, for example:

http://planningpages.midsuffolk.gov.uk/online-applications/centralDistribution.do?caseType=Application&keyVal=_MSUFF_DCAPR_109532

but when I click on it to open it, the link that is opened is:

http://planningpages.midsuffolk.gov.uk/online-applications/centralDistribution.do?caseType=Application\\&keyVal=_MSUFF_DCAPR_109532

It appears that claws is rewriting the URL (two added backslashes) and
that causes the request to fail with an error page.

Does anybdoy recognize this problem?

Cheers, Dave

PS I am using Firefox 48.0 (openSUSE - 42.1)