New comment by akhiljalagam on void-packages repository

https://github.com/void-linux/void-packages/issues/8923#issuecomment-1173685029

Comment:
manual method using deb package

1. download deb package from https://updates.getmailspring.com/download?platform=linuxDeb
2. extract it using `ar x mailspring-*-amd64.deb`
3. now extract data using `tar xf data.tar.xz`
4. `sudo chown root:root usr/`
5.`cd usr`
6.`sudo rsync -avh bin share /usr`

done.
now you can open mailspring and use it.