Product » A free email server for Windows and Linux » Knowledge Base

Document information

Document ID:5032
Subject:Importance of a DNS server in Xeams
Creation date:9/12/16 5:21 PM
Last modified on:8/15/18 11:28 AM


Importance of a DNS server in Xeams

Selecting a faster DNS server is extremely important in Xeams. Several rules, such as RBL Lookups Black-listed domain lookup, MX, A, SPF lookup and others run queries against a DNS server. The faster the lookups, the faster Xeams will be able to process incoming messages.

By design, DNS servers create a lookup chain. For example, if a DNS server cannot resolve a query locally, it will try getting that answer from the next server up. The more servers that are involved in a lookup, the slower a result is fetched and Xeams will spend a longer time processing an email.

When it comes to DNS servers, bigger is better. Every DNS server will cache results. Therefore, it is always better to use a DSN server that will have a large cache.

Often, administrators use a local DNS server, running on their LAN. Relatively speaking, this local DNS server's cache will be significantly less than the DNS server for your ISP. Therefore, we strongly recommend using a DNS server belonging to your ISP instead of your router or another DNS server on your LAN.

WARNING!

DO NOT use a public DNS server, such as Googles (8.8.8.8). For some reason, Google's DNS server does not work nicely with RBL servers. Check this link on SpamHaus for details.

Where to specify a DNS server

Although there is a way to specify a DNS server in Xeams, we recommend you change the DNS server at the machine level where Xeams is running. That is because your machine also contains a cache and will make subsequent lookups faster.



Add a comment to this document

Do you have a helpful tip related to this document that you'd like to share with other users?

Important: This area is reserved for useful tips. Therefore, do not post questions here. Instead, use our public forums to post questions.