Email forwarding issue

I have a website at classicalmusiccity.com. We have emails tied to that domain that forward to a gmail account. Everything has been fine and dandy until a couple days ago. No one can send an email to any address with a @classicalmusiccity.com domain. I get an email back saying "Delivery Status Notification (Delay)" and the email points me here:https://support.google.com/mail/answer/7720 which says that our email may be blocked or mx records are wrong.

Some people tell me google is blocking the resquest, but this issue happens with all email providers, even obscure ones like protonmail. What's going on?

Answer

Currently, your MX record is

[me@risby financial]$ dig mx classicalmusiccity.com.
;; ANSWER SECTION:

classicalmusiccity.com. 14400   IN      MX      0 classicalmusiccity.com.

which in turn resolves to a pair of A records:

[me@risby financial]$ dig classicalmusiccity.com.
;; ANSWER SECTION:
classicalmusiccity.com. 14400   IN      A       192.230.66.31
classicalmusiccity.com. 14400   IN      A       192.230.74.31

neither of which actually answers on port 25:

[me@risby ~]$ telnet 192.230.66.31 25
Trying 192.230.66.31...
Connected to 192.230.66.31.
Escape character is '^]'.
Connection closed by foreign host.
[me@risby ~]$ telnet 192.230.74.31 25
Trying 192.230.74.31...

Connected to 192.230.74.31.
Escape character is '^]'.
Connection closed by foreign host.

We can't say whether those are supposed to be your two mail servers. If they are, they're not working, and you should fix them. If they're not, you should either fix your A records, or your MX record, for at least one of them is wrong.