nmh does not support maildir; it uses its own (rather similar) format known as “mh”. I’ve used nmh for over a decade, but mostly due to inertia. nmh has some i

nmh does not support maildir; it uses its own (rather similar) format known as “mh”. I’ve used nmh for over a decade, but mostly due to inertia. nmh has some issues displaying and (especially) replying to some of the crazier modern formats, although it does a much better job now than even just a few years ago. At this point I’m experimenting with alternatives. I too have concerns about its security (I fear anything from crufty C exploits to MIME parsing exploits to spec‐compliant misfeatures that leak privacy). Maildir is supported by a variety of software I’m interested in (mblaze, mu, notmuch), and honestly I think it’s a better format: the good things about mh format (easy shell manipulation with one mail per file) without some of the less desirable parts (for instance, Maildir keeps flags in the filename, while mh marks the message with custom headers, thus modifying the content).