The contact form is only sending emails in mime Format 
Author: Peter S.I am using Website X5 Pro 2021.2.5 and our domain email. Our hosting company has PHP higher than the 7.3.
Here is a header and a bit received from a enquiry..
This is a multi-part message in MIME format.
--b1_Y3M0dicO7tSp6ZwoO8Y578S3qYGY9Ks0w4oyiOa24
Content-Type: multipart/alternative;
boundary="b2_Y3M0dicO7tSp6ZwoO8Y578S3qYGY9Ks0w4oyiOa24"
--b2_Y3M0dicO7tSp6ZwoO8Y578S3qYGY9Ks0w4oyiOa24
Content-Type: text/plain; charset=us-ascii
Katrina, here is an enquiry from the website that needs a response.. Pete
Name:: Peter
Email address:: XXXXX@outlook.co.nz
Phone number:: xxxx22122
Message:: TEST 1111
--b2_Y3M0dicO7tSp6ZwoO8Y578S3qYGY9Ks0w4oyiOa24
Content-Type: text/html; charset=us-ascii
www.websitex5.com">
APPRECIATE SOME HELP WITH THIS.. Thanks
In the admin panel (place / admin behind your website you can test different scripts for mailing.
The login and password are in x5 step 1 -> acces management -> advanced tab
Test and see what scriptt works best.
Then set this script in step1 -> datamanagement
Check also your provider in there FAQ you should find rues for sending mail ,some have special rules (like you need to use and email adress from the provider)
That can also be an issue, so don't forget to check that as well if above does not work.
Goodluck.
search x5 with Pauls search
Author
Thanks for all that.. Problem solved..My hosting provider offer PHP8.0 by default..
Downgraded/Changing the PHP to 7.3 and email is now great..
Will Website X5 Pro 2021.2.5 be supporting PHP8.0 shortly
Thanks
pro 2021.2.5 already is for PHP v8.
But mail depends on scripts as well (depends on mail system privider).
So do the mail scrpipt test in the admin panel as suggested, mayby you will find a script that wors also on v8.
Author
Ok, Thanks.. will play with the scripts.. I'm very happy having the solution...