Had no idea they also owned Newton. Going to use this as yet another reminder not to invest in new email clients, they all seem to get shut down within a few years of launch.
Newton Mail’s send later’s “don’t send if recipient emails me before sending” feature looks really nice. Aside from that I can’t tell why I’d use Newton over Apple Mail.
I mean outside of any specialized features that the email client hosts, the majority of the functionality is local, no? So even if the email client is no longer developed, it'll keep working as long as your email service works.