Steps to reproduce the issue

Try to register on the frontend of Joomla 4 when mail is not set up - so that the registration mail fails.

The site admin gets a "Private Message" telling them that the email was not sent.

The message of that private message has some weird concat of sentences.

Expected result

"An error was encountered when sending the user registration email. The user who tried to register is: adam"

Actual result

"An error was encountered when sending the user registration email. The error is: The user who tried to register is: adam"

System information (as much as possible)

Additional comments