/etc/hosts broken

thufir@dur:~$
thufir@dur:~$ swaks
To: [email protected]
=== Trying dur.bounceme.net:25...
=== Connected to dur.bounceme.net.
<-  220 dur.bounceme.net ESMTP Postfix (Ubuntu)
 -> EHLO dur
<-  250-dur.bounceme.net
<-  250-PIPELINING
<-  250-SIZE 10240000
<-  250-VRFY
<-  250-ETRN
<-  250-STARTTLS
<-  250-ENHANCEDSTATUSCODES
<-  250-8BITMIME
<-  250 DSN
 -> MAIL FROM:<thufir@dur>
<-  250 2.1.0 Ok
 -> RCPT TO:<[email protected]>
<** 450 4.1.8 <thufir@dur>: Sender address rejected: Domain not found
 -> QUIT
<-  221 2.0.0 Bye
=== Connection closed with remote host.
thufir@dur:~$
thufir@dur:~$ swaks
To: thufir@localhost
=== Trying localhost:25...
=== Connected to localhost.
<-  220 dur.bounceme.net ESMTP Postfix (Ubuntu)
 -> EHLO dur
<-  250-dur.bounceme.net
<-  250-PIPELINING
<-  250-SIZE 10240000
<-  250-VRFY
<-  250-ETRN
<-  250-STARTTLS
<-  250-ENHANCEDSTATUSCODES
<-  250-8BITMIME
<-  250 DSN
 -> MAIL FROM:<thufir@dur>
<-  250 2.1.0 Ok
 -> RCPT TO:<thufir@localhost>
<** 450 4.1.8 <thufir@dur>: Sender address rejected: Domain not found
 -> QUIT
<-  221 2.0.0 Bye
=== Connection closed with remote host.
thufir@dur:~$
thufir@dur:~$ cat /etc/hosts
127.0.0.1	localhost
127.0.0.1       dur.bounceme.net

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
thufir@dur:~$
thufir@dur:~$