Spam is silent
No one sends you a notice when your email goes to spam. You see it only as fewer opens and fewer replies, which is easy to blame on the copy or the list.
Email deliverability
Email deliverability you build once and watch every day.
Great copy is wasted in the spam folder. FirstSales gives you every layer of email deliverability in one place: SPF, DKIM and DMARC, your own tracking domain, a 21-day warm-up, clean lists, safe daily limits and guardrails that pause a campaign before your reputation takes the hit.
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- 01
SPF, DKIM, DMARC and a tracking domain, step by step
- 02
21-day warm-up in 3 phases with a clear Warmup Score
- 03
Sender Health flags the one mailbox dragging a campaign down
- 04
Auto-pause at 5% bounce or 0.1% spam complaints
The problem
Good cold email is worthless if nobody sees it.
When mail lands in spam, nothing tells you. Open rates just fade, replies stop, and by the time you notice, the domain has already lost trust.
Deliverability is a stack, not a switch
Authentication, tracking, warm-up, list quality and sending pace all count. Skip one and the others cannot make up for it, so piecing tools together leaves gaps.
One bad send costs months
A dirty list or a cold mailbox pushed too hard can damage a domain in a day. Rebuilding that trust takes far longer than losing it.
How it works
Set the foundation, then let the guardrails watch.
Email deliverability in FirstSales has two halves. The setup you do once per domain and mailbox, and the checks that run on every campaign after that.
- 01
Authenticate and track
Add SPF, DKIM and DMARC for each sending domain, with a one-click option on Cloudflare. Then point a tracking subdomain at FirstSales with one CNAME.
- 02
Warm up and clean
Turn on the 21-day warm-up for each new mailbox and switch on Contact cleaning, so campaigns skip dead addresses instead of bouncing on them.
- 03
Send with guardrails
Keep daily limits modest, watch Sender Health in each campaign and arm Delivery Protection, so a campaign pauses itself if bounces or complaints spike.
The deliverability stack
Six layers, and each one leans on the one below.
Deliverability is not one setting. It is a stack, and the order matters. A warm mailbox cannot rescue mail that fails authentication, and a clean list cannot rescue a cold mailbox. Build it from the bottom up.
- 6GuardrailsProtectsStops a bad send before it reaches a blocklist.In FirstSalesSender Health and Delivery Protection
- 5Sending paceProtectsKeeps each mailbox at a human, modest volume.In FirstSalesDaily Limit per mailbox, tuned nightly
- 4Clean listsProtectsStops bounces before they hit your reputation.In FirstSalesContact cleaning on import
- 3Warm-upProtectsGives a new mailbox a sending history before real volume.In FirstSales21 days in 3 phases, with a Warmup Score
- 2Tracking domainProtectsKeeps your links off a shared host other senders may have burned.In FirstSalesOne CNAME, SSL set up for you
- 1AuthenticationProtectsProves the mail really comes from your domain.In FirstSalesSPF, DKIM and DMARC, with a Cloudflare one-click
Work the stack in this order when something goes wrong, too. If the lower layer is broken, fixing a higher one will not help.
What you get
Every deliverability layer, in the tool you already send from.
No separate warm-up tool, no separate cleaning tool, no guessing which one broke. The whole stack lives next to your campaigns.
Authentication made simple
Step-by-step records for SPF, DKIM and DMARC on any registrar, plus a one-click setup on Cloudflare with a scoped token that is used once and never stored.
Your own tracking domain
Open, click and unsubscribe tracking runs on a subdomain you own, so your links never share a reputation with other senders.
21-day warm-up
New mailboxes ramp up over 21 days in three phases. The Warmup Score shows when a mailbox is Healthy enough for campaign volume.
Contact cleaning
Addresses are checked on import for MX records, mailbox reachability, disposable and role addresses, with typos fixed, so campaigns skip dead ones.
Sender Health
Each campaign shows a card per mailbox with its warm-up score, bounce rate and sent count. A red outline points at the one sender causing trouble.
Delivery Protection
Arm auto-pause per campaign. If bounces pass 5% or spam complaints pass 0.1%, sending stops before the damage spreads.
From a cold mailboxto a protected campaign
Four parts of email deliverability you will use every week, and what each one shows you.
- Warm-up
Know when a mailbox is ready for real volume
Every sending mailbox has a Warmup tab with a score from 0 to 100. A new mailbox climbs through the 21-day warm-up and reads Healthy at 80 and up. Under 50 it is flagged as a low warm-up score, and under 40 it reads Issues. Wait for Healthy before you put campaign volume on it.
- One clear score. 0 to 100, with Healthy, Warming and Issues bands.
- Three-phase ramp. 21 days, so volume grows the way a real sender's would.
- Maintenance after. Warm-up keeps running quietly once the mailbox is Healthy.
- Clean lists
Stop bounces before they happen
Turn on Contact cleaning in Settings, under Tools. FirstSales checks every address as it comes in: it looks for MX records, tests whether the mailbox is reachable, spots disposable and role addresses and fixes common typos. Campaigns then skip the dead addresses, which keeps your bounce rate low.
- Checked on import. No extra step before each campaign.
- Typos fixed. Common domain misspellings are corrected, not dropped.
- Dead addresses skipped. Campaigns never send to them, so they never bounce.
- Sender Health
Find the one mailbox dragging a campaign down
When a campaign sends from two or more mailboxes, its Analytics tab shows a Sender Health row. Each card shows the sender, a warm-up gauge, bounce rate and sent count. A card turns red when bounces pass 5% or the warm-up score drops under 50, and the red icon tells you exactly which line it crossed.
- A card per sender. Warm-up, bounce rate and sent count side by side.
- Exact issue text. For example, High bounce rate (7.2% > 5%).
- Click to drill in. Open that mailbox's sent emails for the dates you loaded.
- Delivery Protection
Let a campaign pause itself before it hurts you
In a campaign's Settings tab, turn on Auto-pause when delivery health degrades. It is off by default, so arm it on every real campaign. Set the bounce line (5% by default) and the spam complaint line (0.1% by default). If either is crossed, sending stops so you can find the cause.
- Sane defaults. 5% bounce and 0.1% spam, the widely cited danger lines.
- Stricter if you like. Go down to 1% bounce or 0.01% spam on fragile domains.
- Per campaign. Each campaign gets its own brakes.
The lines that matter
Three numbers tell you when to keep going and when to stop.
You do not need to read a dozen charts. Bounce rate, spam complaints and warm-up score cover most of what goes wrong. These are the same lines FirstSales uses for its own warnings and auto-pause.
Bounce rate
Keep going
Under 2%
Watch closely
2% to 5%, amber warning
Stop and fix
Over 5%, red flag and auto-pause line
Spam complaints
Keep going
Well under 0.1%
Watch closely
Creeping toward 0.1%
Stop and fix
0.1% or more, the campaign pauses
Warmup Score
Keep going
80 and up, Healthy
Watch closely
50 to 79, still warming
Stop and fix
Under 50, Low warmup score
The red lines are fixed at 5% bounce and a warm-up score of 50. Delivery Protection lets you set stricter pause lines per campaign, down to 1% bounce or 0.01% spam.
Plain guide
Email deliverability, explained without the jargon.
What email deliverability means, why cold email is judged more strictly than other mail and the handful of habits that keep you in the inbox.
- 01
What email deliverability means
Email deliverability is whether your email reaches the inbox, not just whether it was sent. A message can be accepted by the receiving server and still land in spam, where almost nobody reads it. Good deliverability means mailbox providers like Gmail and Outlook trust your domain and your mailbox enough to put your email where the reader will see it.
- 02
Why cold email is judged harder
Cold email goes to people who have never heard from you, so providers have no history between you and the reader to lean on. They judge you on everything else: whether your domain is authenticated, how old and warm your mailbox is, how many of your emails bounce and how many readers mark you as spam. That is why each layer of the stack matters more for cold outreach than for a newsletter.
- 03
Authentication comes first
SPF lists who may send for your domain. DKIM signs each message so it cannot be changed in transit. DMARC tells receivers what to do when a message fails those checks. Unauthenticated mail is the single biggest spam trigger, and nothing higher in the stack can fix it. Set all three for every sending domain before anything else.
- 04
Why warm-up matters
A brand new mailbox has no reputation. If it starts by sending hundreds of cold emails, it looks like a spammer, because that is what spammers do. Warm-up builds a normal sending history first, with volume that grows over 21 days. In FirstSales the Warmup Score shows when that history is strong enough, at Healthy, 80 and up.
- 05
Bounces are reputation poison
A bounce tells the provider you are sending to addresses that do not exist, which is what careless senders do. Keep your bounce rate under 5%, and ideally under 2%. The biggest lever is cleaning the list before you send. Contact cleaning in FirstSales checks each address on import, so campaigns skip the dead ones instead of bouncing on them.
- 06
Content still counts
Perfect authentication will not save salesy, link-heavy or image-heavy mail. Keep cold emails short, plain and personal, with one clear ask and at most one link. Write the way you would to a colleague. Spam complaints come from readers who feel spammed, so targeting the right people matters as much as the words.
- 07
How to check where you land
FirstSales does not include a seed inbox test or a blocklist lookup. Inside the app, watch the signals that drive placement: authentication status, Warmup Score, Sender Health and your open and reply trend. If you want an outside check, use a separate seed test service, then ramp volume back up slowly rather than jumping straight to full send.
Quick triage
Something looks wrong? Start with the symptom.
Most deliverability problems show up as one of a few symptoms. Match yours, check the likely cause first and use the fix that lives in the app.
| What you see | Check first | Fix in FirstSales |
|---|---|---|
| 1Opens near zero, replies gone quiet | Mail is landing in spam, usually missing authentication | Confirm SPF, DKIM and DMARC all show verified |
| 2Authentication is green, still no opens | A cold mailbox or a shared tracking host | Warm the mailbox to Healthy and verify a tracking domain |
| 3Bounce rate climbing | Dead or mistyped addresses in the list | Turn on Contact cleaning and re-check the list |
| 4Campaign paused itself | A Delivery Protection line was crossed | Find the cause in list or targeting before you resume |
| 5One sender card is red | That mailbox has high bounces or a low warm-up score | Open the card, then clean the list or rest the mailbox |
Before every campaign
An email deliverability checklist
Run through it before you launch, and again whenever opens start to slip.
- SPF, DKIM and DMARC show verified for each sending domain
- Each sending domain has its tracking domain at Verified
- Every sending mailbox reads Healthy (80+) on its Warmup tab
- Contact cleaning is on, so dead addresses are skipped
- Daily limits are modest, with Auto-adjust on
- Volume is spread across several warmed mailboxes
- Delivery Protection is armed on the campaign
- Emails are short and plain, with one clear ask
- You know who you are writing to and why it fits them
- You check Sender Health after the first day of sending
“If you are looking to fix your sales pipeline, you should definitely try [it]. My open rate has increased drastically. The UI and UX are easy to understand, even for a beginner like me.”
Pooja Dhole@ThisIsPoojaD · XBefore and after
Managing deliverability, the patchwork way and with FirstSales
The same goal, staying in the inbox, handled two very different ways.
Separate tools
Five logins and no single view.
- A separate warm-up toolOne more login and one more bill.
- Cleaning in a spreadsheetExport, upload, re-import, repeat.
- DNS records by guessworkCopied from a forum post and hoped for.
- Shared tracking linksYour clicks share a host with strangers.
- No sign of troubleYou learn about spam from a quiet inbox.
- No brakesA bad list keeps sending until someone notices.
With FirstSales
The whole stack next to your campaigns.
- 21-day warm-up built inWith a Warmup Score per mailbox.
- Contact cleaning on importDead addresses are skipped automatically.
- Guided authenticationStep by step, or one click on Cloudflare.
- Your own tracking domainOne CNAME, SSL handled.
- Sender HealthThe struggling mailbox is outlined in red.
- Delivery ProtectionAuto-pause at the lines you set.
Why teams switch
Email deliverability: FirstSales compared with a typical tool
Many tools send email. FirstSales is built so the layers that keep you in the inbox come with the tool, not as add-ons.
| What you get | Typical tool | FirstSales |
|---|---|---|
| Authentication help | Varies | Step-by-step records, Cloudflare one-click |
| Tracking domain | Varies | One CNAME, automatic SSL |
| Warm-up | Varies | 21 days in 3 phases, with a score |
| List cleaning | Varies | Contact cleaning on import |
| Per-mailbox health | Varies | Sender Health cards per campaign |
| Auto-pause | Varies | Bounce and spam lines per campaign |
| Mailboxes | Varies | Unlimited, on every plan |
| Price | Varies | From $29/mo, no deliverability add-ons |
| Start your $1 trial | ||
What people say
From people who use it
Real words from real users. No paid reviews.
“User Interface, Ease of Use, Able to hit the inbox in the first attempt.”
Sadashiv B.
Founder, small business
“One of the biggest pains in cold email is making sure that you have your DNS setup correctly. Firstsales has created a system to make sure you have done this correctly.”
Mike O
Trustpilot review
“I have always struggled in cold outreach. However, Firstsales has provided an excellent tool for cold outreach.”
Kaushal S.
Founder, small business
Go deeper
- Email warm-upHow the 21-day, three-phase warm-up builds trust for each new mailbox.
- Email authenticationSet up SPF, DKIM and DMARC for every sending domain.
- Email verificationClean lists so your campaigns do not bounce.
- Sending infrastructureUnlimited mailboxes, safe daily limits and your own tracking domain.
- Campaign monitoringKeep an eye on every campaign once it is live.
Questions,answered plainly.
Can’t find yours? Write to us.
01What is email deliverability?
It is whether your email reaches the inbox rather than the spam folder. It depends on authentication, mailbox reputation, list quality, sending volume and content, all working together.
02What is the biggest factor in landing in the inbox?
Domain authentication. Mail that fails SPF, DKIM or DMARC is treated as suspicious, and nothing else can make up for it. Set all three before you send.
03Does FirstSales have a spam test or blocklist lookup?
No. There is no in-app seed inbox test or blocklist lookup. FirstSales focuses on the levers that drive placement: authentication, tracking domain, warm-up, Contact cleaning, Sender Health and Delivery Protection. Use an outside service if you want a seed test.
04How long does warm-up take?
The warm-up runs for 21 days in three phases. Watch the Warmup Score: Healthy is 80 and up. Under 50 the mailbox is flagged as a low warm-up score.
05What bounce rate is safe?
Keep it under 5%, and ideally under 2%. Over 5% the app flags a high bounce rate, and it is the default line where Delivery Protection pauses a campaign.
06Is Delivery Protection on by default?
No. It is off by default and set per campaign in the Settings tab. Turn it on for every real campaign. The defaults are 5% bounce and 0.1% spam complaints.
07Why don't I see the Sender Health row?
It only appears for campaigns that send from two or more mailboxes. Add a second sender and it shows up in the campaign's Analytics tab.
08My authentication is green but I still land in spam. Why?
Then look at warm-up and content. A fully authenticated but cold mailbox still lands in spam, and so does salesy or link-heavy copy. A shared tracking host can also drag placement down.
Outreach that keeps going after you log off.Leads, emails, follow-ups and replies, handled.
Connect unlimited mailboxes and let AI agents find leads, write each email and follow up. Or send your own templates in manual mode. From $29/mo.
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