Mail log problem -

[Mike Wright]

<snip />
> The maillog does show some cryptic [to me] errors:
> 
> Jun 28 16:36:55 box6 sendmail[1091]: l5SKaLF4001091: 
> to=bobgoodwin at wildblue.net, ctladdr=root (0/0), delay=00:00:34, 
> xdelay=00:00:30, mailer=relay, pri=989592, relay=[127.0.0.1] 
> [127.0.0.1], dsn=5.6.0, stat=Data format error
> Jun 28 16:36:55 box6 sendmail[1091]: l5SKaLF4001091: l5SKaLF5001091: 
> DSN: Data format error
> 
> Perhaps someone can tell me what this means?
> 

DSN = delivery status notification

Found this on google:

if your sending machine does not have it's own name/IPaddress in
its /etc/hosts file, it will cause the upstream target/relay host
to reject the message with something which means: "I don't know who
you are". The sending MTA sendmail then issues the error in the
maillog "...dsn=5.6.0 stat=Data Format Error". The fix for this is
to have a correct /etc/hosts;

The advice to fix your dns seems to be spot on.

:m)