Wasn't there an EFF or Mozilla project to make e2e encryption as easy as using signal? Some code was written, I think even a plugin for thunderbird for testing

Wasn't there an EFF or Mozilla project to make e2e encryption as easy as using signal? Some code was written, I think even a plugin for thunderbird for testing. Anyone remember the name? I think basically it would lookup the recipients email address to see if they were a user. If not, they would send a invite type message. If they were a user then it would lookup their public key and encrypt it. I think it was PGP compatible, basically just some glue to replace the PGP usablility issues related to key generation, web of trust, etc.