Tell you subscriber to switch to a more robust mail system, perhaps not
operated by or dependent upon his current ISP:

http://www.system.com/

At 04:55 11/22/2002 Friday, Michael Quinion wrote:
 >A subscriber's system has been bouncing all LISTSERV messages. The
 >IT manager at the subscriber's site reported "They are being blocked
 >by our firewall since they are using a non-standard Received header.
 >They need to straighten their act out!" and quoted the following log
 >entry:
 >
 >> 11246618 11/20/02 13:04:36 smtp-proxy[31031] [164.76.102.107:63666
 >> 192.168.0.29:25] (spamscreen) Found spam from 164.76.102.107 (forged
 >> Received: header) from [log in to unmask]