Skip Navigation

[Resolved] Toolset User Form Email Notifications are being blocked

This is the technical support forum for Toolset - a suite of plugins for developing WordPress sites without writing PHP.

Everyone can read this forum, but only Toolset clients can post in it. Toolset support works 6 days per week, 19 hours per day.

Sun Mon Tue Wed Thu Fri Sat
- 9:00 – 13:00 9:00 – 13:00 9:00 – 13:00 9:00 – 13:00 9:00 – 13:00 -
- 14:00 – 18:00 14:00 – 18:00 14:00 – 18:00 14:00 – 18:00 14:00 – 18:00 -

Supporter timezone: Asia/Karachi (GMT+05:00)

This topic contains 4 replies, has 2 voices.

Last updated by Brian 11 months, 3 weeks ago.

Assisted by: Waqar.

Google Error.png

I am trying to: Send toolset user form email notifications from the site when a new user registers.

Link to a page where the issue can be seen: hidden link (this is where the form is filled/ submitted).

I expected to see: Emails coming into the inbox when the registration form was submitted.

Instead, I got: Google blocking the email notifications because they are not RFC compliant. We reviewed with Google, who says the issue is "550-57.1 duplicate headers", even though only one recipient is entered. We have tried adjusting the form Notification e-mail body and other settings, but they still are not coming through.



Thank you for contacting us and I'd be happy to assist.

To troubleshoot this, I'll need to see how this form notification is set up in the admin area.

Can you please share temporary admin login details, in reply to this message?

Note: Your next reply will be private and making a complete backup copy is recommended before sharing the access details.


CV Form.png

Hi Waqar,

I have attached a screenshot of the notification settings. We also tried stripping back the notification email body and disabling all other notifications, but none of these steps resolved the issue. Please let us know if you need any additional information.

Thanks again; your support is greatly appreciated!


Thank you for sharing the screenshot.

I've performed some tests on my website, but couldn't reproduce the issue with the email notification delivery.

Note: On my test website, I couldn't make the 'WP Mail SMTP' plugin work, so I used the 'Post SMTP' plugin instead.

Are the regular WordPress emails from your website (for example the forget password email) getting delivered correctly?

To troubleshoot this further, I'll suggest the following steps:

1. Please test the email notification with all extra plugins disabled and with a default theme like Twenty Twenty-One.

2. Also check if switching from the 'WP Mail SMTP' plugin to the 'Post SMTP' plugin has any effect.

3. And see if changing 'from' and 'to' email addresses, makes any difference.

I hope these tests will help and let me know how it goes.


My issue is resolved now. Thank you!

This ticket is now closed. If you're a Toolset client and need related help, please open a new support ticket.