[Mailman-Users] Mailing List not receiving emails

[Neilrey Espino]

Hi guys,

I have created a list called "group-mailman"....  I sent some invites
and people responded and now have 10 members. But when they try to send
a message they got the following error messages :

"The e-mail account does not exist at the organization this message was
sent to.  Check the e-mail address, or contact the recipient directly to
find out the correct address."

I verified with netstat -na,,,,  port 25 is indeed open,,,,

What else can I possibly look into ?

Many thanks.

neilrey