Migrated site but now Mailing List and Form not working

Hi I moved a site to a new server but now the Mailing List subscribe and the form arent working.

Using v2.4.0

When I put my email address into the Mailing List subscribe, the confirmation email address enevr arrives.

And when I fill out the form the email address I have put into the form send never receives the email.

They are working fine on the site on the original server

Does anyone know the problem?

Cheers