Free WordPress email authentication plugin: Mail Auth Check.
Find out why your WordPress emails land in spam. Mail Auth Check is a small, free plugin I wrote that checks the SPF, DKIM and DMARC records behind your site’s email and explains each result in plain English, right inside Tools and Site Health. It reads public DNS only, sends nothing anywhere and adds nothing to the front of your site.
Or call or text (502) 387-1142
Websites I have built for Kentucky businesses
The most common WordPress complaint is not really a WordPress problem.
A contact form that “stopped sending” is one of the calls I get most. Most of the time the form works fine. The email it sends is rejected or filed as spam, because the domain it comes from is missing an SPF include, has no DKIM key for the service that sends it, or has no DMARC record at all.
Gmail and Yahoo now require every sender to set up SPF or DKIM, and bulk senders to set up all three, under Google’s email sender guidelines and Yahoo’s sender best practices. Microsoft set the same three for high-volume senders to Outlook.com. Mail Auth Check puts the answer where a site owner already looks, in Site Health, so the problem is visible before a customer says they never heard back.
Three records, explained like a person would.
Who may send as you
Confirms there is exactly one SPF record, that it does not end in a dangerous +all, and counts the DNS lookups it uses, following every include, against the limit of ten in the SPF standard.
Signed mail
Looks for published DKIM keys under the selector names used by Google, Microsoft 365, Brevo, Mailchimp, Zoho, Fastmail and others. Developers can add more selectors with a filter.
What happens to failures
Reads your DMARC policy, tells you whether it protects the domain yet, and points out when no report address is set so you never see who is sending as you.
Set up the WordPress email authentication plugin.
Download
Get the version 1.0.0 zip from the button on this page. It is free and licensed under the GPL, like WordPress itself.
Upload
In WordPress, go to Plugins, Add New, Upload Plugin, choose the zip and activate it.
Read the results
Open Tools, Site Health for the three email tests, or Tools, Mail Auth Check for the full report with the records shown.
Fix the records
Change DNS where your domain is hosted, then press Check now to confirm. Results are cached for twelve hours otherwise.
What it does not do.
It does not change DNS
Records are edited where your DNS lives, such as Cloudflare, GoDaddy or your host. The plugin tells you exactly what to change.
It does not send test emails
It only reads public DNS records, so it never adds to your mail volume or touches your inbox.
It cannot see every DKIM key
Keys can sit under any selector name. If yours is unusual, the plugin says it may exist and shows you where to confirm it.
Want it fixed instead of explained?
If the report shows problems and you would rather not edit DNS yourself, that is exactly the job I do on fix my form emails: one SPF record that includes every service that sends as you, DKIM for each one, a DMARC policy that protects the domain, and a real test from your website’s forms to Gmail and Outlook.
Prefer to check without installing anything? The free SPF, DKIM and DMARC checker runs the same checks in your browser for any domain. Both come from the same work I do on the sites I host and maintain.
Mail Auth Check, answered.
Is the plugin really free?
Yes. It is free to download and use on any number of sites, and it is licensed under the GPL like WordPress itself. There is no paid version and no upsell inside it.
Does it collect any data?
No. It reads public DNS records through PHP on your own server. It sends nothing to me or anyone else, adds no tracking and loads nothing on the public side of your site.
Which domain does it check?
The domain in the From address your site uses for email, after any SMTP or email plugin has changed it. You can enter a different domain on the Tools, Mail Auth Check screen.
Will it slow my site down?
No. It runs only in the admin area, when Site Health or its own report is opened, and keeps the results for twelve hours.
Which WordPress and PHP versions does it need?
WordPress 6.2 or newer and PHP 7.4 or newer. I test it on the current WordPress release.
Can you fix the records for me?
Yes. That is a short, fixed-scope job. Tell me your domain and which emails go missing, and I will tell you what I see first.
Emails still going missing?
Send me your domain and tell me which messages disappear. I will look at the records and tell you what is wrong, whether or not you hire me.
Connect with me
Tell me which emails go missing.
What happens next
- 01I reply, usually the same day. Every message comes straight to me, not a ticket queue.
- 02A short call. What the site needs to do, who it is for, and what has not worked before.
- 03A written scope and flat quote. Before any work starts, with hosting and ongoing care listed separately.
5.0 on Google · 23 reviews · I usually reply the same day