[exim] 500 error code

Dear all,

Below is the log of one particular delivery which failed. The admin of
o2.pl mail server claims my exim has an error in its configuration. I
wonder what you think:

2007-12-05 02:33:25 1Izj8f-000Dds-1h <=
adwent-bounces@??? H=(lists.lc-words.com) [127.0.0.1]
P=esmtp S=124599 id=01a001c836db$9b8065c0$030ba8c0@agnieszka
2007-12-05 02:33:26 1Izj8f-000Dds-1h == someone@??? R=dnslookup
T=remote_smtp defer (-53): retry time not reached for any host
2007-12-05 02:41:44 1Izj8f-000Dds-1h Spool file is locked (another
process is handling this message)
2007-12-05 02:41:46 1Izj8f-000Dds-1h Spool file is locked (another
process is handling this message)
2007-12-05 02:42:01 1Izj8f-000Dds-1h ** someone@??? R=dnslookup
T=remote_smtp: SMTP error from remote mail server after end of data:
host mx11.go2.pl [193.17.41.141]: 500 Sorry
2007-12-05 02:42:01 1IzjGz-000EEq-R3 <= <> R=1Izj8f-000Dds-1h U=mailnull
P=local S=109292
2007-12-05 02:42:01 1Izj8f-000Dds-1h Completed

He asked me about retry times (F,2h,15m; G,16h,1h,1.5; F,4d,6h) but in
this case I do not think this is the problem of retry time but of his
server giving exim 500 error code which in turn made exim stop trying to
deliver the mail.

If I am wrong in my interpretation, I will gladly submit my config
details but just thougth I would ask you first.

Thank you!

Zbigniew Szalbot