About
comail is a cooperative SMTP relay for atproto identities. It lets small senders get transactional mail past Gmail's reputation filters without enterprise SaaS prices or handing identity over to a third-party provider.
The person behind this
comail is built and operated by @scottlanoue.com, a Washington-based software developer working on open-source infrastructure for atproto.
atproto already provides the portable identity primitive other protocols lack. Email just needed the plumbing to route around the reputation bottleneck. The relay is AGPL-3.0, the Osprey rules are public, and the labeler feed is public, so anyone with the source can read how deliverability decisions get made.
Who's on the contract
The relay is operated by Atmosphere Mail LLC, a Washington State limited liability company formed in 2026 to give the project a stable legal counterparty. The LLC signs agreements, holds infrastructure, and absorbs liability on behalf of the cooperative. It's structured to reinvest revenue into the cooperative rather than operate for profit.
Architecture
Domain ownership is verified via a DNS TXT record (the same
primitive Let's Encrypt and Google Workspace use). Each enrolled
domain gets a DKIM keypair (RSA and Ed25519) whose public keys you
publish in DNS. The relay signs outbound mail, tracks delivery and
bounce outcomes, and emits events to a Trust & Safety rules
engine (Osprey). Osprey-derived signals drive throttling, warming,
and suspension decisions internally. A separate labeler publishes
public atproto identity labels (verified-mail-operator,
relay-member) on member DIDs.
Open, auditable
The relay, admin UI, Osprey rules, and labeler code all live at tangled.org/scottlanoue.com/atmosphere-mail. Bug reports and patches welcome.
Shared infrastructure
Profile-image thumbnails use the public co/infra AT Protocol image CDN.
Reach us
Operational questions: postmaster@atmos.email. Abuse reports: abuse@atmos.email.