Why did applications stop coming from the site from the order forms to the mail?

Question

Email

We have:
Site arthata.by
Application forms. They fall to gmail. Their addressee is [email protected]
Excellent work for more than 3 years
Moving to timeweb hosting
Half a month of work on a new hosting and applications stop coming to the mail. Not even in spam

What is the reason?

Answer 1

Well, as an option, outdated php handler code, not compatible with php 7

Answer 2

I suppose you use sendmail to send?
Change send to smtp.