The problem ContactUs DAO solves

ContactUs DAO enable storing mailing list & contacts on filecoin where community can vote to decide who can contact them and the file is encrypted and only shared to operator (who is sending the message) after DAO approval.

Many communities such as those on meetup.com or facebook group spent years to gain traction while it is often left unactive where no one can in touch, because 1) overrelying on Centralized Platforms which owns the contacts instead of the organizer/community do. e.g. no way to get email at web2 Social platforms (Meetup, Facebook Group, etc) 2) overrelying on Centralized Organizers. If those core member are busy, there is no way to self-organize say communicating with members even for an active community. 3) people are reluctant to share publicly due to spam and privacy concerns

With ContactUs DAO, it is possible to store contacts info such as mailing list in a decentralized perpetual storage (IPFS/Filecoin) with encryption such that privacy is addressed. Communications and sharing of contacts is achieved by smart contract based governance and decentralized operators nodes that handle the dispatch. Only after DAO approval it is possible for operator to decrypt the file and dispatch with API/SMTP to send emails to members, such that the community truly own the mailing list / contacts and no single centralized organizer or malicious actor is owning the list. It also create possibilities for DAO to accept sponsors as a whole and in turn decide if communications / marketing emails is allowed to the list.

Integrating with protocols like https://matrix.org/ is a natural next step, as I believe most web2 communications tools today require centralized contacts storage while web3 socials is yet to get traction and address privacy fully, it is essential to bridge the gap to build more trustless methods where user is able to receive notifications in web2 fashion (email / telegram).

The design also take into concern that only incremental files should be

Challenges I ran into

Exploring native solidity api related to encryption or retrieval, thanks for the tip off by Sarah to use lighthouse which has a mature sdk

Deployed matrix and attempted to integrated the api, while it's is more tricky to demo end to end as quite some setup is needed

Privacy is guaranteed

Due to the Web2 email protocol nature, that part is not possible to be e2e encrypted i.e. email exposed to sender triggering api/smtpprotocol
However nature

With enough publiahers and demand, shuffling individual messages will avoid possibility middleman stealing the whole list.

We can further reward publisher to act honest if signature receipt of mailing server is returned and reconciliation