Hello, I am trying to send or receive mail from mail server in aapanel, it gives me this error:
Some cloud vendors (such as Google, Amazon) close port 25 by default, and you need to contact the vendor to open port 25 before you can use the post office service normally
Port 25 is not Blocked.
The domain name is linked:

..
Can you help me find the solution, and explain to me.
I bought the domain name from namecheap and I'm using digitalOcean