Limitations on the endings of email

Mautic 4.4.9
PHP 8.1
DB: Server-Version: 5.7.42 - MySQL Community Server (GPL)

My problem is:

I cannot send test emails because I am using an incorrect email.

Are there any limitations on the endings of email addresses in Mautic?

Thank you for your response.

None that I am aware of. In fact that is a first I saw anyone bring this on.

The email has to be valid and settings configured properly.

Can you plz check if you have the right email address in Configuration → Email → Email address sent from. Sometimes users add company name there.