Gmail suspicious link message on my email links

My site sends emails to users, gmail has an issue with the links on these emails. On click of my links a message comes up saying:

suspicious link- this was sent from untrusted site. You sure you want to proceed?

Has anyone come upon this and overcome it? If so, how?

Details: my emails use smtp, have dkim, spf, and dmarc, they all pass. spam score 0.8, which is low.
The link is different than the text.

The anchor href sends the user to youtube actually, and the text of which is the title of the video user is directed to.
OR it is a link to activation page, text is “Click to Activate”.

My site is https and of course gmail and youtube are https.