403 Forbidden error - Sending email with html tags

Installing my Dolibarr
1

Dear community,

Fresh installation of Dolibaar. I’ve added suppliers, customers, users (with HTML signatures), products etc. and all has been going well.
I’ve created a proposal successfully and PDF has been generated nicely.

Problem is, when I try to ‘Send by EMail’ to the customer, I get an error:

“Forbidden
You don’t have permission to access /comm/propal/card.php on this server.
Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request.”

What i have noticed is if there are any HTML attributes in the body of the message, the error occurs.
If I send just plain text even though its using WYSIWYG, this works.

I have a HTML signature attached to my user card, which I would like to include in my emails, therefore plain text isn’t suitable.

WYSIWYG module is enabled (i’ve tried turning on and off)
I’ve tried both PHP mail, and Swift Mailer options.
I’ve tried to manually upload a newer version of CKeditor 5, didn’t work.

Any advice would be appreciated.

Pièces jointes :

2

I tried added the following lines to .htaccess as recommended from this source:

<IfModule mod_security.c>
  SecFilterEngine Off
  SecFilterScanPOST Off
</IfModule>

that didn’t work for me.

By turning of ‘mod_security’ in PHP, i’m able to send html emails.
This however, is a security concern and I therefore need to find a better solution.

Also, CKEditor is re-formatting my HTML signature and making it look pretty ugly. Would be great if the formatting wouldn’t change.

Any help greatly welcome. thank you.