[exim] Multiple log entries for same mail

Hi,

I have these entries in my logs.

2011-02-01 12:27:43 1PkFKh-000DSD-7B <= mail
2011-02-01 12:27:43 1PkFKh-000DSD-7B SMTP error from remote mail server
after initial connection: host fenman.co.uk.s200a1.psmtp.com
[207.126.147.10]: 451 not currently accepting mail from your ip - psmtp
2011-02-01 12:27:43 1PkFKh-000DSD-7B SMTP error from remote mail server
after initial connection: host fenman.co.uk.s200a2.psmtp.com
[207.126.147.12]: 451 not currently accepting mail from your ip - psmtp
2011-02-01 12:27:43 1PkFKh-000DSD-7B SMTP error from remote mail server
after initial connection: host fenman.co.uk.s200b1.psmtp.com
[207.126.147.13]: 451 not currently accepting mail from your ip - psmtp
2011-02-01 12:27:43 1PkFKh-000DSD-7B SMTP error from remote mail server
after initial connection: host fenman.co.uk.s200b2.psmtp.com
[207.126.147.14]: 451 not currently accepting mail from your ip - psmtp
2011-02-01 12:27:43 1PkFKh-000DSD-7B == lindsey@??? R=relay_110
T=smtp_110 defer (0): SMTP error from remote mail server after initial
connection: host fenman.co.uk.s200b2.psmtp.com [207.126.147.14]: 451 not
currently accepting mail from your ip - psmtp
2011-02-01 21:42:46 1PkFKh-000DSD-7B => lindsey@??? R=relay_110
T=smtp_110 S=9853 H=fenman.co.uk.s200a1.psmtp.com [207.126.147.10]
C="250 Thanks"
2011-02-01 21:42:46 1PkFKh-000DSD-7B Completed

Any ideas why the same message is repeated 4 times before the failed
delivery message and then not tried again for 9 hours. I did check the
Q around midday and mail was going out at a steady rate. A client
complained that they sent a mail at midday but it was not received until
22:00 ish so I investigated.
I have just changed the Q runner to run with the -qq option, could this
be the cause.
This is quite a busy server and often has many Q runs running at the
same time.
Could it be that 5 Q runners tried delivery at the same time?
Any suggestions welcome.

Many thanks

David