Domain reputation

A poor reputation sends everything to spam or gets it rejected, and nothing in your sending tool warns you. Reputation also compounds. A clean campaign makes the next one easier to place, while one careless send to a bought list can hurt placement for months. If outreach and customer email share one domain, the damage reaches invoices and password resets too.

• Authenticate the domain with SPF, DKIM and DMARC. These are three DNS records that prove the mail really comes from you.
• Send cold outreach from a separate domain or subdomain, so a bad campaign cannot touch the address your customers rely on.
• Warm up a new domain by starting with a few dozen emails a day and increasing slowly.
• Keep spam complaints low. Google asks bulk senders to stay below 0.10% reported spam and never to reach 0.30%.
• Remove hard bounces straight away and keep the list clean, as described under list hygiene.
• Check Google Postmaster Tools, which shows how Gmail sees your domain.

Every domain that sends email builds a track record. Gmail, Outlook, Yahoo and corporate mail filters watch how many messages bounce, how many recipients mark them as spam, whether people open, reply or delete unread, and whether the sender is properly authenticated. Each provider keeps its own score and none of them shows it to you directly. The score attaches to the domain in the From address, and to the sending servers behind it, not to any single message.

Domain reputation is the long-term memory. A spam score is the verdict on one email.