[Exim] fetchmail/exim pop timeout problem

:
I have a problem with polling our web server (where we collect mail)
If some prat has sent a message to one of my staff with multiple to
addresses, the pop server times out on the first message. This has happened
twice, and of course no further mail comes from this mail box and this
message keeps coming

my fetchmail for the mailbox is

defaults timeout 900 set postmaster mailpoll@mail1 set no bouncemail set
invisible:

poll 208.55.225.118 proto pop3 localdomains 'cyborg-group.com' user
xxxxx password xxxx is * here;

I thin it is something to do with an interaction between exim (3.15) and fetchmail rejecting messages with a too large header.

Is there any way to modify this behaviour so that the mal queue does not time out

I get a error 550 when this happens


any help appreciated