Consult this link:{sample-configuration-prefix-url}/dnsservice.xml[example]
to get some examples and hints.

Specifies DNS Server information for use by various components inside Apache James Server.

DNS Transport services are controlled by a configuration block in
the dnsservice.xml. This block affects SMTP remote delivery.

The dnsservice tag defines the boundaries of the configuration
block. It encloses all the relevant configuration for the DNS server.
The behavior of the DNS service is controlled by the attributes and
children of this tag.

.dnsservice.xml content
|===
| Property name | explanation

| servers
| Information includes a list of DNS Servers to be used by James.  These are
specified by the server elements, each of which is a child element of the
servers element.  Each server element is the IP address of a single DNS server.
The server elements can have multiple server children. Enter ip address of your DNS server, one IP address per server
element. If no DNS servers are found and you have not specified any below, 127.0.0.1 will be used

| autodiscover
| true or false -  If you use autodiscover and add DNS servers manually a combination of all the DNS servers will be used.
If autodiscover is true, James will attempt to autodiscover the DNS servers configured on your underlying system.
Currently, this works if the OS has a unix-like /etc/resolv.xml,
or the system is Windows based with ipconfig or winipcfg. Change autodiscover to false if you would like to turn off autodiscovery
and set the DNS servers manually in the servers section

| authoritative
| *true/false* - This tag specifies whether or not
to require authoritative (non-cached) DNS records; to only accept DNS responses that are
authoritative for the domain. It is primarily useful in an intranet/extranet environment.
This should always be *false* unless you understand the implications.

| maxcachesize
| Maximum number of entries to maintain in the DNS cache (typically 50000)

| negativeCacheTTL
| Sets the maximum length of time that negative records will be stored in the DNS negative cache in
seconds (a negative record means the name has not been found in the DNS). Values for this cache
can be positive meaning the time in seconds before retrying to resolve the name, zero meaning no
cache or a negative value meaning infinite caching.

| singleIPperMX
| true or false (default) - Specifies if Apache James Server must try a single server for each multihomed mx host

| verbose
| Turn on general debugging statements
|===
