Postfix - Cannot received email from some domain
I am using Postfix as my mail server. I do not know why i can send out an email to all the domain but i cannot receive email from some of the domain.
i can send email to both email@example.com & firstname.lastname@example.org . But when email@example.com reply the email, i CAN receive the email. And, when firstname.lastname@example.org reply the email, i CANNOT receive the email.
Anybody can tell me what happen to my main.cf configuration.
Hope someone can help me. Thanks.