Something is not quite right.
Thanks again for taking the time to reply to my question. This time, the solution didn't work. Now, I don't know whether that's due to improper configuration or that there is an issue with the mail server. ISP Config 3, says all green and that everything is good with the mail server.
Here is my configuration for client.com:
A Record for website:
A Record for mail:
A record for www:
MX record for mail:
Do you recognize any issues with the configuration? Recommendations?