Not receiving email notification

Over the last few weeks, I've received an uptick in people using gmail who aren't receiving our emails.  Is there something I can do to change this?  They come to our site, enter a first name and email and then the results go to their email.   Many gmail users are emailing telling me that they aren't receiving their results.  Thank you!

Hello,

We had an email issues recently. JotForm emails are falling into spam folders of some of the email providers. Could you please check your email spam box? If JotForm emails are there, could you please select all of them and mark them as not spam.

Thank you. Please contact us, if you need further help.