mail delayed, why ?

[Siegfried Kerkow]

Hello

I had running qmail on an machine. This machine is now changed. I
copied all qmail stuff from the old to the new machine. And I checked
all permissions. All may run very well - but now incoming mails have
a delay up to an hour befor they are delivered to there mailbox.

Where can I search for this error? Someone an idea?
Sorry for my bad english.
Sigi.