What is a good cold email deliverability rate?

Aim for 95%+ delivered and under 2% bounce. If bounce goes above 3%, stop sending and re-verify the list — mailbox providers treat high bounce as a spam signal within days.

Do I need a separate domain for cold email?

Yes. Always send cold email from secondary domains that look like your brand, never from your main company domain. If a secondary domain gets burned, your main domain and internal email stay untouched.

How long should email warmup take?

Two to three weeks per new inbox. Start at 3–5 emails a day and add roughly 5 per day until you reach 25–30. Rushing warmup is the single most common cause of a domain landing in spam.

Do SPF, DKIM and DMARC really matter for cold email?

They are mandatory. Google and Microsoft enforce authentication for bulk senders, and a missing DMARC record alone can push everything you send into spam regardless of copy quality.

How do I know if my emails are landing in spam?

Reply rate is the honest signal. If open tracking shows above 40% but replies sit below 1%, you are likely in Promotions or spam. Run a seed test across Gmail, Outlook and a corporate tenant every two weeks.

Deliverability

Cold Email Deliverability Checklist

Deliverability is not one setting — it is about fifteen small ones. This is the checklist we run before the first email of any campaign goes out, and the weekly checks that keep domains healthy afterwards.

By Karolis Pečiūra · Founder, AREM Sales

Published August 12, 2026 · 8 min read

1. Domain and inbox setup

Buy 2–4 secondary domains that resemble your brand (try-, get-, -hq, .co variants). Never send cold email from your primary domain
Put 2–3 inboxes on each domain — more than that on a fresh domain looks artificial
Set up a real redirect from each secondary domain to your main site; a domain with no website is a spam signal
Use Google Workspace or Microsoft 365 rather than cheap SMTP relays — reputation is inherited from the platform
Give every inbox a real name, photo and signature; empty profiles look like bots

2. Authentication (non-negotiable)

Record	What it does	Check
SPF	Authorises who can send for the domain	One SPF record only — two records break both
DKIM	Cryptographically signs your mail	2048-bit key, enabled per sending domain
DMARC	Tells providers what to do with failures	Start at p=none, move to p=quarantine after 2 weeks
MX	Receives replies	Must exist, or replies vanish and reputation suffers
Custom tracking domain	Avoids shared, blacklisted tracking links	One per sending domain

3. Warmup

Run warmup for 14–21 days before the first real send, on every new inbox
Start at 3–5 emails per day and increase by ~5 per day
Keep warmup running permanently at a low level, even during live campaigns
Cap live sending at 25–30 cold emails per inbox per day — this is the limit that keeps domains alive
Never move a brand-new domain straight to full volume because a campaign is 'urgent'

4. List hygiene

Verify every list before import; target under 2% bounce, and pause immediately above 3%
Remove catch-all domains or send to them in a separate, low-volume segment
Strip role addresses (info@, sales@, office@) — they hurt reputation and rarely reply
Re-verify any list older than 30 days; B2B data decays about 2% per month
Suppress everyone who has already replied, unsubscribed or bounced, across all campaigns

5. Copy and formatting rules

Plain text only — no images, no HTML templates, no brand banners
One link at most, and none at all in the first email if you can avoid it
Under 120 words; long emails get skimmed and reported
Avoid spam-trigger phrasing: 'free', 'guarantee', 'act now', excessive capitals or exclamation marks
Include a plain one-line opt-out ('Reply STOP and I'll close your file') — it lowers spam complaints
Spin subject lines and opening lines so 500 identical emails are not hitting the same filter

6. Sending behaviour

Randomise delays between sends (60–180 seconds), never send in a burst
Send only during business hours in the recipient's time zone
Spread volume across all inboxes rather than pushing one hard
Stop a sequence the moment someone replies — continuing generates complaints
Keep total daily volume tied to inbox count: needing 500 emails a day means around 17–20 inboxes, not bigger limits

7. Weekly health checks

Check	Frequency	Red line
Bounce rate	Every campaign	Above 3% — stop and re-verify
Reply rate	Weekly	Below 1% with normal opens — likely spam placement
Blacklist scan (domain + IP)	Weekly	Any listing — pause and delist
Seed test (Gmail / Outlook / corporate)	Every 2 weeks	Anything landing outside Primary
DMARC aggregate reports	Monthly	Failures from your own sending sources
Spam complaint rate	Weekly	Above 0.1%

What to do when a domain gets burned

It happens to everyone eventually. The recovery is boring but reliable, and it is why you always run more than one sending domain.

Stop all cold sending from that domain immediately
Keep warmup running on it for 3–4 weeks with zero campaign volume
Fix the root cause — usually a bad list or too much volume too fast — before restarting
Rotate live campaigns onto healthy domains so pipeline does not stop
If reply rate does not recover after a month, retire the domain and buy a new one; the cost is trivial next to lost pipeline

FAQ

What is a good cold email deliverability rate?: Aim for 95%+ delivered and under 2% bounce. If bounce goes above 3%, stop sending and re-verify the list — mailbox providers treat high bounce as a spam signal within days.
Do I need a separate domain for cold email?: Yes. Always send cold email from secondary domains that look like your brand, never from your main company domain. If a secondary domain gets burned, your main domain and internal email stay untouched.
How long should email warmup take?: Two to three weeks per new inbox. Start at 3–5 emails a day and add roughly 5 per day until you reach 25–30. Rushing warmup is the single most common cause of a domain landing in spam.
Do SPF, DKIM and DMARC really matter for cold email?: They are mandatory. Google and Microsoft enforce authentication for bulk senders, and a missing DMARC record alone can push everything you send into spam regardless of copy quality.
How do I know if my emails are landing in spam?: Reply rate is the honest signal. If open tracking shows above 40% but replies sit below 1%, you are likely in Promotions or spam. Run a seed test across Gmail, Outlook and a corporate tenant every two weeks.

Want this run for you?

We book qualified B2B meetings with cold email and cold calls — first meetings usually land within 2–3 weeks.

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