Grade your sending setup.Inbox or spam is decided here.
Great copy never gets read if it lands in spam. Inbox placement isn't luck, it's infrastructure: who you send from, whether you're authenticated, how clean your list is, and how you warmed up. Check off what's true for your setup and get a deliverability grade plus the precise fix for every box you can't tick.
Your sending setup
Tick every check that's true for how you actually send. Each box is weighted by how much it moves inbox placement.
Your score
Deliverability setup
F
2 of 10 checks passing
Check by check
Custom sending domain (not free webmail)
You send from a domain you own, not gmail.com or outlook.com. You can't authenticate or build reputation on free webmail, and bulk senders to Gmail/Yahoo are required to use a real domain.
SPF record published
A DNS SPF record lists the servers allowed to send for your domain. Without it, receivers can't tell your mail from a spoof. Publish one before anything else.
DKIM signing enabled
DKIM cryptographically signs each message so receivers can verify it really came from you and wasn't altered. Turn it on in your ESP and add the published key to DNS.
DMARC policy at least p=none
DMARC tells receivers what to do when SPF/DKIM fail and reports who's sending as you. Start at p=none to collect data, then tighten to quarantine or reject.
Domain / IP warmed up before volume
A new domain with no history looks suspicious. Ramp from a trickle of mail to your engaged contacts up to full volume over two to four weeks before sending at scale.
Bounce rate under 2%
High bounces signal a dirty or scraped list and crater reputation fast. Validate at signup and remove hard bounces immediately, never re-send to them.
Opt-in list, no purchased lists
You only mail people who asked to hear from you. Purchased and scraped lists spike spam complaints, the single most damaging deliverability signal there is.
Visible unsubscribe link
Passing (+6).
Plain-text part alongside HTML
Passing (+6).
Sending volume ramped gradually
Even on a warm domain, a sudden volume spike looks like a hijacked account. Grow sends in steady steps rather than one big blast.
Your move
Authenticated, warmed, and still landing in spam? Let's find the leak.
Your sending setup scored 12/100 (F) — 2/10 checks passing.
Deliverability is a chain, and one weak link sends the whole campaign to junk. Run your setup through the scorecard, then bring me what's left. In 30 minutes I'll tell you whether the problem is auth, reputation, list quality, or the message itself, and what to fix first. Free, yours to keep either way.
Plain English
Mailbox providers decide inbox vs spam in milliseconds.
Email deliverability is whether your message actually reaches the inbox, not whether it was 'sent.' Your email service provider will happily report a 99% delivery rate while half your sends quietly route to the spam folder. 'Delivered' just means the receiving server accepted the message. 'Inbox placed' is the number that pays you, and it's a different number entirely.
Gmail, Outlook, and Yahoo make the inbox-or-spam call using signals you control before you ever write a subject line: are you sending from a real domain you own, have you published SPF, DKIM, and DMARC so the provider can verify it's really you, did you warm the domain up gradually instead of blasting volume on day one, and is your list opt-in and clean enough that people don't mark you as spam. Get those wrong and the best campaign in the world dies in the junk folder.
This scorecard grades the infrastructure side, the part that's mechanical and fixable, rather than the message itself. Tick the boxes that are true for your current setup. Every box you can't tick comes with the specific fix, so you leave with a prioritized punch list instead of a vague feeling that 'deliverability is bad.'
The formula
Deliverability score = sum of the weights of every setup check you pass (out of 100)
A new sender on a free Gmail address with no SPF, DKIM, or DMARC and a purchased list might tick only 'visible unsubscribe' and 'plain-text part', scoring 12/100, an F, and a one-way ticket to spam. Add a custom domain, publish all three auth records, warm up, and clean the list and the same sender clears 90, an A, with inbox odds to match.
What your score buys you
Providers don't publish exact thresholds, but the relationship between setup quality and inbox placement is well established. Where your score lands maps to the odds your mail actually gets seen:
| Score | Inbox odds |
|---|---|
| 90–100 | Strong |
| 70–89 | Decent |
| Below 70 | Expect spam folder |
Source: Compiled from Google & Microsoft sender guidelines · 2025
Your score came back low. Fix in this order.
Sending from a free webmail address (gmail.com, etc.).
Stop here, nothing else matters yet. You can't authenticate mail you don't own the domain for, and DMARC at Gmail/Yahoo now effectively requires it for bulk senders. Move to a custom domain before you fix anything else.
Missing SPF, DKIM, or DMARC.
These three records are table stakes. SPF says which servers may send for you, DKIM cryptographically signs the mail, DMARC tells receivers what to do when checks fail. Publish all three; a single missing record can tank placement on its own.
Authenticated but new domain / IP.
A clean setup with zero sending history still looks suspicious. Warm up: start with tens of emails to your most engaged contacts and ramp volume over two to four weeks. Sudden volume on a cold domain reads exactly like a spammer.
List quality is the gap (bought lists, high bounces, no opt-in).
Engagement is the strongest modern signal. Purchased lists spike complaints and bounces, which is the fastest way to get filtered for everyone. Send only to people who opted in, scrub bounces, and sunset contacts who never open.
How to drive your deliverability score up
01Send from a domain you own
A custom sending domain is the foundation of every other signal. You can't authenticate, brand, or build reputation on free webmail, and bulk senders to Gmail/Yahoo are now required to use one.
02Publish SPF, DKIM, and DMARC
All three, not one or two. SPF authorizes your servers, DKIM signs each message, DMARC sets the policy and gives you reports. Together they tell mailbox providers you're real.
03Warm the domain up
Ramp from a trickle to full volume over two to four weeks, sending to your most engaged contacts first. Reputation is earned by consistent, wanted mail, not a single big blast.
04Keep bounce rate under 2%
High bounces signal a dirty or scraped list and crater reputation fast. Validate addresses at signup and remove hard bounces immediately, never re-send to them.
05Only mail people who opted in
Purchased and scraped lists generate spam complaints, the single most damaging signal there is. Permission-based sending keeps complaints near zero and engagement high.
06Make unsubscribe one click
A visible, honored unsubscribe (and a list-unsubscribe header) means unhappy readers leave quietly instead of hitting 'report spam', which is far more costly to your reputation.
07Always include a plain-text part
Send multipart emails with both HTML and a plain-text version. HTML-only mail looks lower quality to filters and breaks for clients that strip HTML.
08Ramp volume gradually, every time
Even on a warm domain, a sudden 10x spike looks like a hijacked account. Grow sending in steps and keep your day-to-day volume steady.
09Watch engagement, prune the dead
Opens, clicks, and replies tell providers people want your mail. Periodically suppress contacts who've ignored you for 90+ days, they drag your whole list down.
10Monitor your DMARC reports and blocklists
Set DMARC to collect aggregate reports and check the major blocklists. You can't fix a reputation problem you can't see, catch it before placement craters.
The vocabulary
- Deliverability
- Whether your email reaches the inbox, as opposed to spam or being blocked. Distinct from the 'delivered' rate, which only means the server accepted it.
- SPF
- Sender Policy Framework: a DNS record listing the servers allowed to send mail for your domain, so receivers can spot spoofing.
- DKIM
- DomainKeys Identified Mail: a cryptographic signature on each message that proves it came from your domain and wasn't tampered with.
- DMARC
- A policy (p=none, quarantine, or reject) that tells receivers what to do when SPF/DKIM fail, plus reporting on who's sending as you.
- Warmup
- Gradually increasing sending volume on a new domain or IP so mailbox providers build trust instead of treating you as a sudden spammer.
- Complaint rate
- The share of recipients who hit 'report spam.' Keep it well under 0.1%; it's the most damaging deliverability signal there is.
Deliverability questions, straight answers
There's no official scale from mailbox providers, but the relationship is clear: the more of the core setup checks you pass, the higher your inbox odds. On this scorecard, 90+ (an A) means a strong, authenticated, well-warmed sender with clean lists. Below 70 you should expect a meaningful share of mail in spam. The fastest gains are almost always authentication (SPF, DKIM, DMARC) and list hygiene.
Keep going
A calculator tells you what. A call tells you what to do about it.
Send me the account behind these numbers. I'll tell you straight where the money's leaking and what I'd fix first — free, and you keep it whether you hire me or not.