Problem with Distribution List

Hi guys,

I have a problem when i try to send message (no encrypted) to distribution list. Appears the following message:

Your message did not reach some or all of the intended recipients.                Subject:        Usar Lync                Sent:           07/11/2014 11:39:00 a. m.PGP: Message is blocked - recipient email address could not be resolved. Error code: [0xa1010013].The original message is embedded in this non-delivery report. Click Send Again to see the original text and have the opportunity to re-send the message. If the problem persists and you still receive another non-delivery report, please contact your administrator for details.Error Details:Your message cannot be delivered because SMTP address(es) of some recipient(s) present in a distribution list could not be resolved.

I readed the article http://www.symantec.com/docs/TECH205906  . My problem is that the distribution list is very big and i don´t manager it.

Any idea..?

Thanks.

NOTE: I have SED 10.3.2 Build 15238