Problem with Gmail

I have a form set up on my website to gather data from potential customers

The form sends the email ok but it keeps ending up in my Gmail spam folder. I have tried adding the site to Gmail contacts, and also tried to add a filter, but nothing seems to work.

I will attempt to contact Gmail support for an answer, but I thought maybe someone here might have run into the same problem.

Any help would be greatly appreciated.

http://findalandsurveyor.com/survey-my-land/

https://ww.wp.xz.cn/plugins/si-contact-form/