Some of my Support tickets arrive in the Spam folder of the receiver

Some of my Support tickets arrive in the Spam folder of the receiver

Hi,

I have tested the Zoho Support a bit with several different e-mails. Some of the mails/tickets I send with Zoho Support arrive in the Spam folder, for example at my Gmail account. Gmail says the mail is classified as spam mail, but they give no reason WHY. No special text in the mail, just plain writing as I always do.

Any idea? Can I solve this?

thanks,
marc