[fetchmail]Fetchmail doesn't seem to like the SMTP server hanging up on it?

[Ed W]

I have been testing the effects of tightening up some of the postfix 
options.  In particular I set the hard error limit to 1 so that people 
relaying via web proxys get chucked off as soon as they send any invalid 
smtp command.  However, I notice that this seems to cause a problem with 
fetchmail when I reject an invalid address with a 554 response.  It 
seems that fetchmail doesn't read the response in this circumstance, 
hence doesn't flush/bounce the message and everything backs up.

Loosening up the postfix options seems to allow me to download mail again.

Is this a known issue?

Thanks

Ed W