Yaguare,
Thanks for reaching out! Not sure exactly why this is happening, but this depends a lot on your email providers spam filtering settings. I would contact them to see if there is some kind of whitelist your site could be put on.
Since spam filtering settings are specific to each individual email provider and we don’t have any control over that, we unfortunately can’t offer further advice than that.
Hope that helps, and just let us know if you have further questions. Thanks!