Email Forwarding not working gmail detected virus

Hi!

I’m trying to set up e-mail forwarding but it doesn’t seem to be working. I tried several options to redirect, both to a Gmail address and my own mail address, but it keep getting back with a virus warning.

I don’t want to use third party.

I’m not able to find the default DNS settings either. Does someone have these for me, so I can check these are all correct? I took over a webshop from someone and want to double check the issue isn’t due to incorrect DNS settings. Domain was purchased via Shopify.

Thanks a bunch!