Why don't hosting companies allow external email addresses to be entered in the form? And is it right?

Question

Email

The hosting company does not allow sending applications to external mail. Is this behavior justified?

Answer 1

You can send mail not through the hosting server, but through phpmailer for example or swiftmailer and already register any mailing addresses in them

Answer 2

Justified, in order to combat spam. The scale of the problem is really that serious.