Webform Email Does Not Pass DMARC

Question

I am setting up DMARC, SPF and DKIM records for the first time. I'm using WordPress, Elementor, SiteGround, and Google Workspace.

When submitting a Form from my website, sent from arandomemail@mysite.com, my email sends the form submission to spam. I did expect this to happen because I set my p value to quarantine. But, I don't know how to ensure my form sends to my inbox.

Also, my form submission comes back neutral on SPF and fail on DKIM

A couple things I do want:

1. Only arandomemail@mysite.com should be able to pass quarantine (I assume this is a best practice to ensure that only arandomemail@mysite.com has the potential to be spoofed)
2. Ideally, arandomemail@mysite.com would only be allowed to send emails to a certain email(s) address - like sales@mydomain.com. (This I assume helps flag any emails spammers send from my domain to to external people).

If I am going about this all wrong, please point me in another direction that abides by current best practices.

A few other notes that might be helpful:

• We're only sending email from gmail via siteground
• the domain is not registered with siteground but uses siteground nameservers

Answer 1

I'm the author of an open source contact form that can be used on websites. Here is what I do to allow my webservers to send email to my domain and pass all spam checks:

Contact form configuration:

1. The contact form should be configured to only send to a preconfigured email address or list of email addresses at your domain. If your contact form allows email to be sent to arbitrary address off of your domain, you should find better contact form software.
2. The contact form should send all message from your own email address. If you try to have your contact from send emails as if they came from the user that submitted the form, the emails will be rejected as spam. The contact form should set the reply-to address to that of the user submitting the message so that you can respond, but send the mail from your own address.

Sending configuration

Rather than trying to send email from your server directly, I recommend configuring the email to be sent through your normal SMTP server. This usually involves configuring your web server with the email address and password of the email account from which it is sending email.

Most contact forms don't try to connect directly to your SMTP server to send the emails, rather they use a command line program called sendmail. The method for sending mail is configured through sendmail rather than within the contact form itself. For example if sendmail is provided by exim4 on an Ubuntu system, the instructions for configuring it are on Ask Ubuntu: How do I configure exim4 to send mail through a password protected ssl smtp mail server?

When your server is configured to talk to your mail server like a normal user, sending mail works just as well as it does for normal users. You don't have to do any special DKIM and SPF setup to allow your web server to send mail directly.