[XCSSA] failed emails

[X-otic Computer Systems of San Antonio]

I keep getting message from a mailing list for winmodems in Ubuntu. My
mails are sent back to me. What is causing this?

Hi. This is the qmail-send program at
 ns0.crynwr.com.
I'm afraid I wasn't able to deliver your message
 to the following addresses.
This is a permanent error; I've given up. Sorry
 it didn't work out.

<discuss at linmodems.org>:
ezmlm-reject: fatal: Sorry, I don't accept
 messages of MIME Content-Type 'multipart/alternative'
 (#5.2.3)

-- 
Christopher Lemire <christopher.lemire at gmail.com>