[Mailman-Users] Fw: Mailman not delivering e-mails sent from Yahoo

[The Knight]

Hello everyone, 
We are using Mailman Version 2.1.9 the problem we are facing is when we use a Yahoo e-mail ID to send an e-mail to a mailing list it reaches mailman but when i Accept it as a moderator it's not delivered to subscribers of the list. I tried with Gmail and MSN everything works fine but this only happens when sent from Yahoo.
If anyone has had a similar problem please let me know what solution did you apply ?
Thank you