[Mailman-Users] New member confirmation email

[Hung Phan]

Hi, all. I've been looking for answer to this mystery problem. My  
mailing list is setup requiring new members to confirm their  
subscriptions along with a welcome message. But the confirmation  
email and welcome message never come. In the Mail Queue (OS 10.4.7),  
they never make it to the queue.

Have anyone run into this problem? What may cause this behavior?
Thank you so much for your help.