What mailbox format is being used during the failures, maildir or mbox? Might make a difference. (I've always thought maildir is safer than mbox, because one maildir file gets corrupted and one message is lost, while one mbox bit gets flipped and all the messages are lost.)
dep Pictures: http://www.ipernity.com/doc/depscribe/album Column: https://www.athensnews.com/opinion/columns/the_view_from_mudsock_heights/