DSN: Data format error

[Timothy Murphy]

When I send email with
--------------------------
[tim at carrie ~]$ mail -s "Test 2" gayleard at eircom.net
Testing ...
Cc:
--------------------------
I get the above error message in /var/log/maillog .
More fully, I get
--------------------------
Sep 20 14:42:22 carrie sendmail[17175]: m8KCgMOa017173:
to=<gayleard at eircom.net>,<tim at maths.tcd.ie>,
ctladdr=<tim at carrie.gayleard.com> (500/500), delay=00:00:00,
xdelay=00:00:00, mailer=relay, pri=150351, relay=smtp.eircom.net
[159.134.198.135], dsn=5.6.0, stat=Data format error
Sep 20 14:42:22 carrie sendmail[17175]: m8KCgMOa017173: m8KCgMOa017175: DSN:
Data format error
Sep 20 14:42:22 carrie sendmail[17175]: m8KCgMOa017175:
to=gayleard at eircom.net, delay=00:00:00,xdelay=00:00:00, mailer=relay,
pri=31582, relay=smtp.eircom.net, dsn=2.0.0, stat=Sent (ok 1221918274 qp
15906)
--------------------------

What exactly is DSN?
As far as I can see from google, it stands for "Data Source Name".
But what does "dsn=2.0.0" mean?

As far as I can see, this error only arose recently.
I'm running Fedora-9 with kernel 2.6.26.3-29
and sendmail-8.14.2-4 .

I should say, this only occurs when I send mail as above
with the "mail" command.
If I send it from within KMail, as normal, it is sent OK.




-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland