> > Removing or deleting a single message from near the beginning of a > > large flat file takes an inordinate amount of time because the > > remainder of the flat file has to be rewritten all the way from the > > point of the deleted message to the end of the file and then > > truncated. > > maybe why postfix only support maildir++ > > all other formats is properitary formats
This 'performance statement' is not even correct under some conditions. I have tested mbox against mdbox, and mbox performed better in those tests.