No? Version 1.3 was tagged in the repo September 13 this year.

https://github.com/leahneukirchen/mblaze/tags

And correspondingly of course that’s the version package repos have/will published too.

For example, Alpine Linux has that version in a community package repo on a branch.

https://pkgs.alpinelinux.org/package/edge/community/x86/mbla...

FreeBSD package repo is a little behind, still on v1.2 instead of v1.3. But that’s still a version from March of this year.

https://www.freshports.org/mail/mblaze

And even if the most recent release of mblaze really had been a few years ago, it could still be good software. Especially for email.