How to prevent spam from being emailed to my clients?

Do I need to upgrade my membership to prevent spam from being emailed to my clients? I'm getting unhappy reports of too much spam.

Unfortunately, we are not spamming your clients. Our product is a form builder, a webmaster tool that many small or medium businesses use to build forms.

Could you please provide the spam email that they're receiving so we can investigate it further? You can also provide the email address of your client so we can check it further.

We'll wait for your response. Thank you.