Deliverability best practices
Deliverability is mostly reputation: mailbox providers learn from how recipients react to your mail. SpacePost gives you the infrastructure; these habits protect the reputation.
Checklist
Section titled “Checklist”Authentication
- Domain verified with all three DKIM records (guide)
- Return-path (
send) MX and TXT records verified so SPF aligns - A DMARC record published, starting with
p=none(DMARC) - Send from a domain you own, never a free mail address like
gmail.com
Lists
- Only email people who opted in; confirm signups with a double opt-in if you can
- Never send to addresses you did not collect yourself
- Remove addresses that bounce (SpacePost suppresses hard bounces automatically)
- Stop emailing people who never open after several months
- Make unsubscribing obvious and instant
Content
- Always include a plain-text part (SpacePost generates one from HTML if you do not)
- A recognisable From name and a real Reply-To
- Subject lines that match the content; no all caps, no excessive punctuation
- Reasonable image-to-text ratio; no giant images as the only content
- Few links, to domains you control; avoid URL shorteners
- A physical address and unsubscribe link in marketing mail
Practice
- Warm up new domains gradually
- Use separate subdomains for transactional (
mail.acme.com) and marketing (news.acme.com) mail - Keep bounce rate under 2% and complaint rate under 0.1%
- Watch webhooks for
bouncedandcomplainedand act on them - Test with the test addresses, never with fake addresses
Targets
Section titled “Targets”| Metric | Healthy | Automatic pause at |
|---|---|---|
| Bounce rate | below 2% | above 5% (at least 10 bounces) |
| Complaint rate | below 0.1% | above 0.2% (at least 3 complaints) |
Rates are measured over your last 1,000 emails. See Automatic pausing.