David wrote:

Doing an MX check for my domain via
https://toolbox.googleapps.com/apps/checkmx/ gives the following errors

- SPF must allow Google servers to send mail on behalf of your domain.
- DKIM is not set up.
- DMARC is not set up.
- No Google mail exchangers found. Relayhost configuration?

That is aimed at checking if your domain is properly configured for use
by GApps, so the errors are not relevant.