On Tue, 12 Aug 2003, Chris Sleep wrote:
> However exim -bt someone@??? shows varying behaviour -
> part of the time it returns the unroutable response, and the rest it
> returns the expected:
>
> router = dnslookup, transport = remote_smtp
> host mail.laurentian.ca [142.51.1.21] MX=10
>
> with debug mode added, it turns out that the unroutables seem to be down
> to an issue with case sensitivity on the name returned by the dns
> lookup:
This bug will be fixed in the next release, which I am hoping to get out
this week or soon after. If you can't wait, the bug is already fixed in
the current snapshot release. This is the ChangeLog entry:
48. Domain names in DNS records are case-independent. Exim always looks them up
in lower case. Some resolvers return domain names in exactly the case they
appear in the zone file, that is, they may contain uppercase letters. Not
all resolvers do this - some return always lower case. Exim was treating a
change of case by a resolver as a change of domain, similar to a widening
of a domain abbreviation. This triggered its re-routing code and so it was
trying to route what was effectively the same domain again. This normally
caused routing to fail (because the router wouldn't handle the domain
twice). Now Exim checks for this case specially, and just changes the
casing of the domain that it ultimately uses when it transmits the message
envelope.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
Get the Exim 4 book: http://www.uit.co.uk/exim-book
