Email deliverability: SPF, DKIM, DMARC and domain warm-up, handled
A great email is useless if it lands in spam. Hemero walks you through the DNS setup, ramps up new domains gradually and stops risky sends before they hurt your reputation.
What email deliverability is
Deliverability is whether your emails reach the inbox, land in spam or get blocked. Mailbox providers such as Gmail, Outlook and Yahoo decide by looking at your domain's reputation, whether your email is properly authenticated, the quality of your list and what the email says.
No honest tool can promise inbox placement, and Hemero doesn't. What it does is build in the safeguards that lower the risk, so a new sender doesn't make the common mistakes.
SPF, DKIM and DMARC in plain words
SPF
#who may sendSPF is a DNS record that lists which services are allowed to send email for your domain. It lets inboxes check that a message came from a server you approved.
DKIM
#signatureDKIM adds a digital signature to every email you send. Inboxes check it against a public key published in your DNS, so they know the email wasn't forged or changed on the way.
DMARC
#policyDMARC tells inboxes what to do with emails that claim to come from your domain but fail those checks, and where to send reports. Hemero recommends starting in monitor-only mode, which blocks nothing, and you can later choose to send suspicious emails to spam or block them.
How to set up your sending domain
Add your domain
Open Domains and click Add domain. Use a domain you control. A subdomain such as news.yourcompany.com is a good choice, because it keeps marketing emails apart from your everyday email. Free addresses like Gmail or Outlook can't be used to send campaigns.
Add the DNS records
Hemero shows the records to add at your DNS provider: DKIM, SPF and MX are required, DMARC is recommended. Use the Copy buttons so nothing gets mistyped. Step-by-step instructions are built in for Cloudflare, GoDaddy, Namecheap, Squarespace and Google Domains, IONOS, Hostinger, Wix and Amazon Route 53, and one button copies a ready-made message for whoever manages your DNS.
Check them
Press Check now. Hemero marks each record as Found, Not found yet or Wrong value, and shows what it found instead. While the page is open it checks again every 30 seconds. DNS changes can take an hour or more, so you don't need to wait on the page.
Start sending
When the setup shows Ready to send, you can send from any address on that domain. The whole setup takes about 10 minutes, plus the wait for DNS.
Add DMARC
Optionally copy the recommended DMARC record, set the policy and the percentage of emails checked, and add where reports should go. Monitor only is the safe choice for most people.
The safeguards that run for you
Domain warm-up
#new domainsMailbox providers are cautious with a new sending domain. Hemero caps the daily volume of a newly verified domain, from a few dozen emails on the first day, and raises it each day until the cap ends after two weeks. Campaigns and automations over today's cap continue the next day. The domain list shows Warming up and the day count, and you can switch the limit off, at the risk of spam-folder placement.
Staged first send
#new contactsPeople you have never emailed before go out in three waves (2%, then 8%, then the rest). The next wave is released about 30 minutes after the previous one finishes, and only if few enough emails bounced. Otherwise the campaign pauses.
Automatic pause
#protectionA campaign or automation that starts bouncing a lot, or gets spam complaints, pauses itself and tells you why. Fix the list and resume it. The app also warns you when your account-wide bounce or complaint rate is high.
Content check
#before sendingBefore a send, the Content check scores the subject, preview text and body and gives a verdict: Good, Fair (worth fixing) or Poor (likely spam). It flags things like ALL CAPS subjects, spam trigger phrases, link shorteners, links that go somewhere other than they say, images without alt text, scripts, a missing unsubscribe link or postal address, and emails big enough for Gmail to clip.
Clean lists
#hygieneImports and signup forms reject invalid addresses, throwaway inbox providers, typos, domains that can't receive email and spam trap addresses. You can also turn on list hygiene in Settings: contacts who never open or click are asked if they still want your emails, and moved to Inactive if they don't answer.
Suppression list
#never againHard bounces, spam complaints, unsubscribes and manual blocks go on your suppression list automatically, and no campaign, automation or API email goes to them. Temporary (soft) bounces such as a full mailbox don't suppress an address.
One-click unsubscribe
#complianceEvery campaign and automation email carries the unsubscribe headers that Gmail and Yahoo require from bulk senders, which show an Unsubscribe button in the inbox, plus a link in the body. Unsubscribing takes effect immediately, and you can brand the unsubscribe page per domain.
Gmail throttling back-off
#providersIf Gmail starts throttling a domain, emails to Gmail addresses are held and then ramped back up over three days, while other providers keep sending.
What it costs
These safeguards are included in every plan with no extra charge, and there is nothing to switch on for most of them. You pay only for the emails you send, from $19 a month for 25,000 emails; see pricing. The contacts page explains imports and suppressions in more detail.
Honest limits
No inbox guarantee
Providers make the final call. Safeguards reduce risk, but a poor list, unwanted email or weak content can still end up in spam.
New domains take time
Warm-up slows down the first big sends on purpose. Plan a large announcement for after the ramp, not the first day.
Shared infrastructure
Hemero sends through shared infrastructure, so it watches bounce and complaint rates across accounts. An account whose rates get too high can have sending paused until it cleans its lists.
Your list matters most
Only email people who asked to hear from you. No tool makes up for a list of people who didn't.
Questions
How do I set up SPF, DKIM and DMARC?
Add your domain under Domains and Hemero shows the exact DNS records, with built-in instructions for popular DNS providers. Add the records, press Check now and wait for each to show as Found. DKIM, SPF and MX are required to send; DMARC is optional but recommended.
What is domain warm-up and how long does it take?
Warm-up means growing the volume you send from a new domain gradually, so mailbox providers learn to trust it. In Hemero it runs automatically for about two weeks after you verify a domain, and you can see the day count on the Domains page.
Why do my emails go to spam?
Common causes are a new or unauthenticated domain, sending to people who didn't ask for your emails, old inactive addresses, spammy wording and broken links. The content check, warm-up and list hygiene address several of these, but the main fix is a list of people who want your email.
Can Hemero guarantee that my emails reach the inbox?
No, and be wary of anyone who says they can. Hemero lowers the risk with authentication, warm-up, automatic pauses and clean lists, but mailbox providers make the final decision.
What happens when someone marks my email as spam?
The address is added to your suppression list so you never email it again, and the complaint counts toward your rates. If complaints climb, the campaign or automation pauses on its own.
Do I need my own domain to send?
Yes. You send from an address on a domain you own and verify with a few DNS records. That is what lets inboxes trust your emails. A subdomain such as news.yourcompany.com works well.
Ready to send with confidence? Create an account, verify your domain and let the safeguards do their work.