Many email providers (like Gmail and Yahoo!) use SPF to ensure that email is allowed to be sent by the server that sent it. They do this by checking your DNS server for an SPF record that says it’s ok for X server (or domain) to send emails for Y domain.
Bidsketch now has a public SPF record published so that you can setup your DNS to include Bidsketch mail servers in your own SPF record. If what I’m talking about here is a bit over your head you might want to consult your host or someone that has experience managing DNS.
That being said, all you have to do is add a new text record in DNS with this in it:
Note that the underscore is there on purpose. So your complete text record might look like this:
v=spf1 mx ptr include:_spf.bidsketch.com ~all
Again, this can be confusing stuff so only mess around with DNS if you know what you’re doing or can get someone else that knows to make these changes.