PHP Mail just suddenly stop working

Question

It's been a while that i have used the php mail function in the contact form of my site to send out emails. Recently, I have found out that it just stop working. When i send an inquiry in my contact form, it says successfully sent but none of the test i did came into my inbox..

Does anyone facing the same issue here? How can i possibly fix this?

I checked the MX entry in cpanel and the data is correct. I want to try SMTP but i dont have access information.

ANy help on this matter?

Additional Information i have found out: Web Server is hosted in one of the hosting company. Mail server is hosted in google.

Where is probably is the problem here?

Answer 1

Probably the problem is with your hosting provider, which "figured out" that your form was generating a lot of traffic and it was blocked.

Answer 2

Or something has gone wrong. Look at /var/log/mail.* for issue.