Thanks for the respond. Yes, I could send email from the mailman list server (by mailx and mail -v) to external email accounts. The email sent to the mailman list server did reach there, but was just stored inside the mailman and didn't post to the members. However, I got the mailman working now by installing and using POSTFIX as the mail server rather than using EIXM4 mail server. Finally, the mailman starts posting email to the members
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