(required) The TCP/IP address of your domain name server.
Lyris will have to be shutdown and restarted in order for a change to this setting to take effect.
Note that if your DNS server is not working, or you give an invalid DNS TCP/IP address in this setting, that Lyris will no longer be able to send email out. In most cases, the Lyris installer will
have placed an appropriate value here.
Lyris will verify any setting you enter by connecting to the IP address you specify, on port 53. If Lyris cannot verify that the DNS server setting is valid, it will not save the setting you
specify, and you will receive a warning message to this effect.
You can specify as many DNS servers as you like. Each TCP/IP address must be on a separate line. If you specify more than one DNS server, Lyris will automatically balance the DNS query load between
them. Also, if one of your servers goes down, Lyris will still be able to send mail if you have multiple DNS servers defined. Note that because Lyris uses an internal DNS caching scheme, the Lyris
DNS cache is equally as effective with one or many servers -- thus, the usual reason for using just one DNS server (to help that server cache entries) does not apply with Lyris.
We recommend that busy sites define as many DNS servers as possible. DNS operations typically are typically a large part of the work in delivering mail, and when there is a great deal of mail to
deliver, DNS server efficiency tends to suffer. Thus, listing many DNS servers will greatly increase your mail sending capacity.