cpanel email account is not receiving email from WordPress
I pointed the A record of my website to another ip address (domain B). So I lost some of the emails during that time. I realised I need to point the MX record back to my server (domain A). What I did is point MX record to mail.domianname.com.au, and point mail.domianname.com.au to A record(domain A's ip address). This is working. However, after while, I found this cpanel email account cannot received emails from my WordPress website, I moved WordPress website to domain B. I try to use WordPress website to send email to my other emails, nothing wrong. That means WordPress is working. And I tried to use gmail to send email to the cpanel email account, also working.
May I know that what I did for MX record is correct or not? Or any other thing I need too do for this?
Thank you in advance.