On Tue, Aug 23, 2005 at 09:17:56AM +0200, Cristiano Cumer wrote: > 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 >
The patch for bigger than 512 byte dns responses is in qmail-ldap since years. -- :wq Claudio
