Aliases and recipients
Confirm the alias exists, is active, and is not disabled. Confirm the destination is a verified recipient and that its address is spelled correctly. Check both the dashboard and the destination spam folder.
SPF, DKIM, DMARC, and DNS
For custom domains or sending, check the MX, SPF, DKIM, and DMARC records requested by the application. DNS changes can take time to propagate. A recipient domain without a DMARC policy can cause reply/send checks to fail.
Spam filtering and provider delivery
Inspect message headers and the spam folder. Providers may initially filter forwarded messages, especially when a domain’s authentication records are incomplete. Do not mark forwarded messages as spam because that can harm the shared sending reputation. Disable a noisy alias instead.
Login
Check the sign-in address, verification email, spam folder, and any browser extensions that block mail or scripts. If the problem persists, contact the operator through the private channel used for your invitation. TODO: publish the operator contact address.
Provider-specific failures
Record the exact bounce text, the sending address, the alias, and the time. Do not retry indefinitely. A 550 rejection can mean the alias is missing or inactive; a reply/send failure can also indicate that the verified recipient’s domain fails DMARC. Redact personal message content before sharing diagnostics.