[fetchmail]Rejecting large messages when using "sendmail" for delivery

[Ed W]

Hi, I have a problem with my config where a large message is being 
downloaded again and again and again.

I have postfix installed locally and was finding problems with feeding 
mail in via SMTP to do with some spam messages being bounced when I 
really want them accepted and filtered locally as spam.  So I am now 
doing delivery via the "sendmail" commandline app.

However, I have a user with a 23Mb email in their pop box and my postfix 
limit here is 20Mb, and the sendmail command appears to be rejecting the 
message with a return code "69" and so the message is not flushed and 5 
mins later we download this beast again...

Can anyone suggest how I can reconfigure fetchmail to work around this?  
I can't see how I can reconfigure the return codes when I am using a 
command line delivery

I could use the "-l" option, but this seems to leave the mail on the 
server and send warnings to the recipient.  This is supposed to be used 
in an ISP type environment, so really I would prefer to bounce the 
message back to the orig sender and hence get them to resend it in a 
smaller format.

Any suggestions?

Thanks

Ed W