======Spam Filter Rules: StartDNS======
^Statement  |StartDNS |
^Version  |2.2.1+ |
^Purpose  |Begins an asynchronous DNS lookup in advance of the result being required in a subsequent [[spamrules_statement_dns|DNS]] statement |

The **StartDNS** statement requires a type and hostname, in the format
  StartDNS <type> <hostname>

The DNS lookup begins immediately, but the script is allowed to continue. When the **DNS** statement is reached, the script will get the result of the corresponding **StartDNS** statement. If the DNS lookup is still in progress, it will allow the lookup to complete, before returning the result.


=====Example=====
<code>
StartDNS MX pscs.co.uk

# Continue with the rest of the script, whilst also running the DNS lookup

# By the time the script reaches the DNS statement, the lookup should either be fully or partially completed.

DNS MX pscs.co.uk dnsresult
</code>