title: SPF for subdomain
body: <p>I need to configure SPF record for a subdomain.</p>
  
  <p>DNS for the main domain (I use Google Mail):</p>
  
  <pre><code>IN MX 1   aspmx.l.google.com.
  IN MX 10  aspmx3.googlemail.com.
  IN MX 10  aspmx5.googlemail.com.
  IN MX 10  aspmx4.googlemail.com.
  IN MX 10  aspmx2.googlemail.com.
  IN MX 5   alt1.aspmx.l.google.com.
  IN MX 5   alt2.aspmx.l.google.com.
  
  IN TXT    "v=spf1 ip4:xx.xxx.xxx.xx include:_spf.google.com ~all"
  
  mysubdomain IN A xxx.xxx.xxx.xxx
  </code></pre>
  
  <p>But how to set SPF for mysubdomain.example.com ? I will send email newsletter from this subdomain using phpmail.</p>
  
  <p>Also online email checkers show warning that there is no MX record for my subdomain.</p>