Hi, I'm having bother trying to debug an occasional issue on my site. I run a PHP mailer script via the CLI to send mail to a few thousand addresses in batches. Occasionally, I get the following error before all emails have been sent:

sendmail: fatal: No recipient addresses found in message header postdrop: warning: stdin: unexpected EOF in data, record type 78 length 276 postdrop: fatal: uid=10003: malformed input

This only happens from time to time. I'm on a Centos 5 server. Can anyone point me in the right direction for what could be happening here?