[SWLUG] postfix errors, help please

[bascule]

i would appreciate any help in interpreting the following system mail:

Postfix SMTP server: errors from localhost[127.0.0.1]
 From: Mail Delivery System <MAILER-DAEMON at watson.excession>
 To: Postmaster <postmaster at watson.excession>
 
Transcript of session follows.

 Out: 220 watson.excession ESMTP Postfix (2.2.5) (Mandrake Linux)
 In:  EHLO localhost
 Out: 250-watson.excession
 Out: 250-PIPELINING
 Out: 250-SIZE 10240000
 Out: 250-VRFY
 Out: 250-ETRN
 Out: 250 8BITMIME
 In:  MAIL FROM:<6Cr2ehDCea at mail.ru> SIZE=13477
 Out: 250 Ok
 In:  RCPT TO:<halmika at theexcession.co.uk>
 Out: 250 Ok
 In:  DATA
 Out: 354 End data with <CR><LF>.<CR><LF>
 Out: 451 Error: queue file write error

Session aborted, reason: lost connection

i'm assuming that this had something to do with the machine 'watson' being 
unreachable over the network when i came home just now and also not showing a 
console over the kvm - forcing me to soft reset, the mail log shows activity 
between the time of the mail - 9:12:28 thurs and now, i'd like to know that 
this error actually means :)

bascule
-- 
"For a moment, nothing happened. Then, after a second or 
so, nothing continued to happen. "