On Sat, May 06, 2006 at 02:42:45PM +0100, Geoff Soper wrote: > I just tried this and there's no delay at any point, each command > returns results near instantaneously. It did inspire me to change the > settings of Squirrelmail from mail.babbnet.com to localhost and this > has sorted out the problem for Squirrelmail, however it's still very > slow for logging in with an IMAP client remotely such as Thunderbird. > This increasingly makes me think it's DNS related, especially bearing > in mind the DNS problems the server had originally (not being able to > resolve external addresses) which support fixed and then the DNS > problem I fixed yesterday (slow to resolve resolve external addresses) > by changing the DNS servers listed in /etc/resolv.conf . I'm certain > it's something configuration based (if not actually DNS) rather than a > fundamental problem as a near identical server I have access to (same > hosting company and product) has no such problems. > Any ideas what to try next?
# tcpdump -i eth0 -n -s1500 -X tcp port 143 and host x.x.x.x where x.x.x.x is the Thunderbird client. Then press the button on Thunderbird to make it collect and retrieve mail. See if the delay is before the TCP connection is opened, or there is a delay between certain IMAP commands and their responses. If the delay occurs before the client sends any packets: then there's a problem with the client configuration trying to resolve mail.babbnet.com to an IP address. (A quick check here suggests that the forward DNS for mail.babbnet.com is configured correctly, but perhaps the client is pointed to two DNS caches, one of which is broken, so it tries that, times out, then falls back to the other) If the client connects immediately, but there's a delay before courier-imap sends the login banner: then there's a problem with your reverse DNS, that is, mapping x.x.x.x to the client's hostname. Sticking an entry for that particular host in /etc/hosts may make the problem go away, however the solution is to fix your reverse DNS. Regards, Brian. ------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Courier-imap mailing list [email protected] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-imap
