PHP8.0 mail() to use /r/n line endings

[matidau]

Used less than PHP 8.0, as this is a breaking change for PHP 7.4.

What does this implement/fix? Explain your changes.

Reported issue for users of PHP8.0+ using PHP mail() to send.

The change for 8.0 is explained well on this Drupal issue https://www.drupal.org/project/drupal/issues/3270647

Does this close any currently open issues?

24 error sending mail: corrupt headers

Any relevant logs, error output, etc?

Just the ones in the issue

Where has this been tested?

Server (please complete the following information):

• OS: Ubuntu 22.04
• PHP Version: 7.4 / 8.0
• Backend for: IMAP / Mail-in-a-Box
• and Version: Mail-in-a-Box v63

Smartphone (please complete the following information):

• Device: Xiaomi 11T
• OS: Android 13
• Mail App: GMail
• Version 2023.07.23