Hullo all,
recently I have noticed problems sending mails to sites with lots of
MX, like gmail. I always get a:
deferral: CNAME_lookup_failed_temporarily._(#4.4.3)/
error
I have found this:
http://www.lifewithqmail.org/lwq.html#dns-problem :
E.2. Why can't I send mail to a large site with lots of MX's?
If you're getting:
deferral: CNAME_lookup_failed_temporarily._(#4.4.3)/
The problem might be that qmail can't handle large name server query
responses. The fix is to install a patch or workaround. See Patches
under Advanced Topics.
There's also a question as to why some people don't have trouble
reaching such systems. Basically, depending on the timing and
ordering of queries made to your local nameserver, the size of the
response to an ANY query for "aol.com" may be larger than the 512
byte limit of a UDP packet, or it may not.
"May not" is likely to happen if the A and MX records time out, but
the NS records don't. Since the .COM servers set a 2 day TTL on
those, but AOL sets a 1 hour TTL on their records, this will often
happen on less busy nameservers. Busier nameservers are more likely
to have those records in their cache at any given time, frustrating
an unpatched qmail's attempts to check for CNAMEs.
A better test is to send mail to [EMAIL PROTECTED]; if it
clears your queue and winds up bouncing from ckdhr.com, your MTA can
send mail to hosts with MX lists that exceed 512 bytes. (By using a
single RRset, with a single TTL, that exceeds 512 bytes, the problem
can be seen without depending on the timing and ordering of other
queries.)
I was wondering if those patches can be merged whit qmail-ldap
Ciao
Cristiano
