We are seeing a slight 30-60 second delay on incomming email, which I've tracked down
to the DNS blacklist lookups. I have a couple of questions regarding how to fix this,
if possible. Granted, I do have 14 rules, which I suppose I could cut back on.
1. Why aren't these queries done in parallel? Could they be? I suspect this would
speed them up by a factor of 10.
2. Is 14 rules too many, or do I just have to live with a 30 delay at this number?
3. Would caching speed this up? I have the iMail DNS cache set to 200. Does this get
used for blacklists? Should I up it?
4. Has anyone implimented some kind of caching on their local DNS server that would
speed this up? We run MS DNS, not sure what the caching is like.
I know a 30-60 second delay is not that bad; email is not IM after all. However, prior
to having spam filtering, it was virtually instantaneous (1-2 seconds). The clients
are givin us a hard time about it, even though they love the spam filtering.
Thanks!
-Chase
Chase Seibert | Network and Systems Engineer | Bullhorn Inc. | 617.464.2440 x119
| www.bullhorn.com
