I get DMARC reports sent from various different sources.
All of the reports generally have `<result>pass</result>` for all of the sections.

However, the reports from Google always have SPF fails:

    <row>
        <source_ip>185.116.215.174</source_ip>
        <count>1</count>
        <policy_evaluated>
            <disposition>none</disposition>
            <dkim>pass</dkim>
            <spf>fail</spf>
        </policy_evaluated>
    </row>
    .
    .
    .
    <auth_results> 
        <dkim>
            <domain>domain.co.uk</domain>
            <result>pass</result>
            <selector>dkim</selector>
        </dkim>
        <dkim>
            <domain>email-od.com</domain>
            <result>pass</result>
            <selector>dkim</selector>
        </dkim>
        <spf>
            <domain>bounce.domain.co.uk</domain>
            <result>fail</result>
        </spf>
    </auth_results>

My SPF record looks like:

`"v=spf1 +a +mx +a:server.domain.co.uk include:email-od.com ~all"`

I am unsure why my bounce domain is failing SPF checks, but it only seems to be on Google DMARC reports.

To be honest, I am unsure what the bounce domain `bounce.domain.co.uk` does, should I set up an email address `[email protected]`?

Any help sorting my SPF and advice regarding `bounce.domain.co.uk` would be great.