Bug#300585: exim4-daemon-light: doesn't correctly handle Backslashes and Capitals in local user account names

[Marc Haber]

Package: exim4-daemon-light
Version: 4.50-1
Severity: normal
Tags: upstream

Hi,

exim refuses to deliver e-mail to local user accounts which have
backslashes or capitals in the account name. It looks like the
recipient's local part is lower cased and has backslash expansion done
to it before check_local_user compares against the local user database.

This makes delivery to user names like Debian-exim and or
DOMAIN\foo impossible.

For backslashes, this can be remedied by doubling the backslash
(DOMAIN\\foo). There is no remedy for the capital case.

Greetings
Marc