Mail deliverability notes

Getting a message sent and getting it delivered — accepted by the recipient's mail provider instead of silently dropped, quarantined, or flagged as spam — are two different problems, and Loombre only solves the first one.

If your outgoing mail server address points at a transactional-relay service or a mailbox provider (see the Admin Guide's Mail page for the reference table), the deliverability groundwork — the SPF, DKIM, and DMARC DNS records that convince a receiving mail server your mail is legitimate — is that provider's job, and their own setup instructions cover it; you generally don't need to touch DNS yourself, and adding those records for a domain you don't control (a shared subdomain a relay service issues you) is usually unnecessary or actively wrong. Sending directly from a home connection's own IP address, with no relay in between, is a different story: most residential and small-business ISP address ranges are pre-emptively blocked or heavily distrusted by major mail providers regardless of how correctly everything else is configured, so direct-send from a self-hosted instance's own address is, in practice, usually futile — route through a relay, or your domain registrar's or ISP's own mail service, instead of fighting that particular battle yourself.

See also

• Mail — the Admin Guide's setup page, and its provider reference table.
• Environment variable reference — every mail-related variable, including LOOMBRE_PUBLIC_URL.