June 30, 2026
Set up your sending domain (or use ours) in an afternoon
TL;DR. You have two paths on day one: send on a shared platform domain with zero DNS setup, or authenticate your own domain with SPF, DKIM, and DMARC. Either way you can be sending the same afternoon — the only real work is three DNS records, and even those are optional if you use ours.
The fastest way to start outbound is to not touch DNS at all: send on a shared platform domain that is already authenticated, and you can have your first email out within minutes. If you want mail to come from your own domain — which most teams eventually do — the work is three DNS records (SPF, DKIM, DMARC) plus a custom MAIL FROM. Add them, wait for DNS to propagate, and you are sending the same afternoon. This post walks both paths so you can pick the one that fits your first week.
Should you use your own domain or a shared one?
It depends on how soon you need replies to come from your real address. A shared platform domain is the zero-setup option: nothing to configure, good enough to learn the product and send your first sequence. Your own domain takes an afternoon of DNS work but means recipients see your brand and can reply straight to you. Most teams start on the shared domain while DNS propagates, then switch.
| Shared platform domain | Your own domain | |
|---|---|---|
| DNS setup | None | SPF, DKIM, DMARC, MAIL FROM |
| Time to first send | Minutes | An afternoon (after propagation) |
| From address | A platform subdomain | Your real domain |
| Reputation | Shared with other senders | Yours alone, built over time |
| Warmup | Handled by the platform | 21-day ramp on new domains |
| Best for | Trials, first sequences | Ongoing outbound at volume |
What is a sending domain?
A sending domain is the domain in the From address that receiving servers — Gmail, Outlook, Yahoo — use to decide whether to trust your mail. They do not judge it by how it looks. They check DNS records published under that domain to confirm the message really came from a server you authorized, and they track that domain's complaint history over time. A brand-new domain with no records and no history looks exactly like a spammer to them.
A common choice is to send from a subdomain — say mail.yourcompany.com or go.yourcompany.com — rather than your root domain. That keeps outbound reputation separate from the domain your team uses for normal one-to-one email, so a rough patch on a campaign does not drag down your everyday mail.
Which DNS records do you actually need?
Three, plus one envelope setting. Each answers a different question the receiver asks.
| Record | What it proves | Minimum in 2026 |
|---|---|---|
| SPF | This server is allowed to send for the domain | v=spf1 include:amazonses.com ~all, under 10 DNS lookups |
| DKIM | The message was not altered and is cryptographically signed | 2048-bit key, rotated annually |
| DMARC | What to do when SPF or DKIM fail | p=quarantine to start, move to p=reject |
| MAIL FROM | Bounce handling and SPF align to your domain | A subdomain like mail.yourdomain.com with MX + SPF |
SPF is a TXT record listing who can send for you. DKIM signs every message so a receiver can verify it was not tampered with in transit. DMARC ties the two together and tells receivers what to do with mail that fails — start at p=quarantine so failures go to spam rather than the inbox, then tighten to p=reject after about 30 days of clean reports. The custom MAIL FROM points the bounce-handling envelope at your own domain so everything aligns.
Do the new Gmail and Yahoo rules apply to you?
If you send roughly 5,000 messages or more per day to personal Gmail or Yahoo accounts, you are a "bulk sender" under rules both providers began enforcing in 2024 and have been ramping up through late 2025. Bulk senders must authenticate with SPF and DKIM, publish a DMARC record (at minimum p=none, though aligned DMARC is recommended and likely to become required), offer one-click unsubscribe on marketing mail, and keep their spam complaint rate below 0.3% — Google advises staying under 0.1% for reliable placement. Smaller senders are not formally bound by the 5,000-per-day threshold, but the same authentication is what keeps any mail out of spam, so set it up regardless. Transactional mail like password resets and order confirmations is exempt from the unsubscribe rule; promotional and outbound sales mail is not.
How long does propagation take?
DNS changes are not instant. Most records show up within a few minutes to a couple of hours, but the published TTL on your records can hold old values for up to 48 hours at some resolvers. Practically, you can usually verify SPF, DKIM, and DMARC within the hour using a validator, then send a test message to a Gmail and an Outlook address and check the headers show pass on all three. Do not start real volume until that test passes.
What about warming up a brand-new domain?
A domain with no sending history has no reputation, and dumping thousands of messages on day one is the fastest way to get filtered. Warmup means ramping volume gradually — a common schedule is around 100 sends a day for the first week, 500 a day for the second, and 2,000 a day for the third before sending at full volume. We cover bounce rates and warmup in depth later in this series; for now, just know that a new domain needs a runway, which is another reason the shared domain is a sensible place to start.
How does SEMAOS handle this?
You can send on the SEMAOS shared platform domain (semaos.io) with no DNS setup at all — SPF, DKIM, DMARC, and MAIL FROM are already in place. When you are ready to bring your own domain, SEMAOS walks you through verifying each record and will not let you send until they pass. New custom domains are automatically held to a 21-day warmup ramp (100 / 500 / 2,000 sends per day) before your plan limits apply, so a fresh domain builds reputation instead of burning it. Pick the shared domain to start outbound today; switch to your own once DNS has propagated.
Next in this series: importing and cleaning your first contact list.