Data Format Error

Christopher Fisk chrisf at
Fri Mar 25 11:39:43 EST 2005

On Fri, 25 Mar 2005, Andrew Brink wrote:

> Hi All -
> I am getting a bunch of these "Data Format Errors" in my sendmail log 
> files.  These are happening mostly when spam gets sent to a user that 
> does not actually have a mailbox.  Below is an example of one message:
> sendmail[1007]: j2PFXQgM001005: to=<aa36987 at>, 
> delay=00:00:00, xdelay=00:00:00, mailer=cyrus, pri=512884, dsn=5.6.0, 
> stat=Data format error
> Any ideas of why I get this instead of just a stat=User Unknown?

I've run into the same issue, and as I'm running my messages through 
MailScanner I've not been able to figure out a solution to get sendmail to 
check for valid users on the cyrus server until after it's accepted the 
message.  As a workaround, (I have a relatively few number of addresses 
that are valid on this server) I have begun using


in my file, then, in my /etc/mail/access I do the following 
for each valid user:

To:user1 at yourdomain.tld		RELAY
To:user2 at yourdomain.tld		RELAY
To:.yourdomain.tld		550 ERROR: NO SUCH USER
To:yourdomain.tld		550 ERROR: NO SUCH USER

Hope that helps, and perhaps someone else will have an answer on getting 
sendmail to check cyrus during the initial connection.

Christopher Fisk
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