From the post [0] and the website [1]: All my projects have been terminated after Google falsely flagged FairEmail as spyware without a reasonable opportunity to appeal. There will be no further development and no more support.
GitHub has the last release as of 2022-05-18 and the repository has been archived by the owner. It is now read-only.
FairEmail was posted on HN just over a year ago [3].
EDIT1: Another post was done earlier [4] linking to an XDA post. Thanks @M66B
EDIT2: Another post was done earlier [5] linking to another XDA post. Thanks @neogodless
[0] https://github.com/k9mail/k-9/issues/655#issuecomment-113164...
[1] https://email.faircode.eu/
[2] https://github.com/M66B/FairEmail/releases
[3] https://news.ycombinator.com/item?id=26386374