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SMTP+ Inboxes

The Secret Weapon for
High Deliverability at
$1/inbox/mo

Fresh Microsoft IPs routed via AWS that aren't hammered by cold emailers. 10 inboxes per domain. 2-day warm-up. No OAuth headaches. Scale to thousands for a fraction of the cost.

That's about 3 cents per day per inbox

How Your Emails Get Delivered

SMTP+ routes through Azure Communication Services via AWS — low fingerprint, high deliverability.

SMTP+ RouteYour email's journey to the inbox
1

Sending Tool

Instantly, Smartlead...

SMTP — No OAuth
2

AWS (US)

Infrastructure Routing

Fresh US-Based IPs
3

Azure Communication Services

Microsoft IP Pool

Low Fingerprint
✓

Recipient Inbox

Primary tab

Delivered
SMTP+Low

Microsoft IPs via Azure Communication Services routed through AWS US. Not associated with cold email.

Microsoft 365Medium

Outlook infrastructure. Good for enterprise. Known cold email provider — some IP reputation risk.

Google WorkspaceMedium-High

Google actively monitors for cold email. Higher disconnect and suspension risk.

Why Agencies Are Switching to SMTP+

Everything you need to send cold email at scale — without the complexity or the price tag.

Fresh Amazon AWS IPs

Microsoft IPs routed via AWS. US-based, clean reputation, not burned by cold emailers.

2-Day Warm-Up

Start sending in 48 hours, not 2 weeks. Launch campaigns faster than any other provider.

No Disconnects

SMTP connection — no OAuth tokens to expire, no re-authentication flows, no surprise disconnects.

10 Inboxes Per Domain

3x more inboxes per domain than Microsoft or Google. Fewer domains to buy, more sending volume.

Bulk Upload via SMTP

No OAuth connections to manage. No two-factor prompts. Just SMTP credentials — paste and go.

Free Swaps — Everything

Swap IPs, domains, and usernames at any time. Completely free. Inbox not performing? Replace it.

See How Much You'll Save

SMTP+ costs less per inbox and needs fewer domains. The savings compound fast.

SMTP+
Microsoft 365
Google
Domains needed
10
34
34
Domain cost / yr
$130
$442
$442
Inbox cost / yr
$1,200
$3,588
$3,960
Total / yr
$1,330
$4,030
$4,402

At 100 inboxes, SMTP+ saves you 0 /year vs Microsoft 365

That's $225/mo back in your pocket. Plus 24 fewer domains to manage.

SMTP vs OAuth — Why SMTP+ Is Simpler

SMTP+ (What you get)

  • Paste SMTP credentials into your sending tool
  • No OAuth tokens to refresh or expire
  • No two-factor authentication prompts
  • No reconnection flows when tokens break
  • Bulk upload hundreds of inboxes instantly
  • Native inbox access still available
  • Works with every sending tool — zero config

OAuth Providers (The headaches)

  • OAuth tokens expire and disconnect inboxes
  • Two-factor prompts block bulk connections
  • Manual re-auth required per inbox
  • Sending tools lose connection randomly
  • Can't bulk upload — one inbox at a time
  • Google requires app passwords or OAuth dance
  • Microsoft tokens expire every 90 days

SMTP+ at a Glance

$1/inbox/mo

Flat rate, any volume

10inboxes/domain

3x more than MS/Google

2day warm-up

vs 14 days for others

$0for swaps

IPs, domains, usernames

The Domain Math

With 10 inboxes per domain, you buy fewer domains. Domain costs are separate — a .com is typically ~$12.99/yr.

10

inboxes per domain

SMTP+

3

inboxes per domain

Microsoft

3

inboxes per domain

Google

For 1,000 inboxes: SMTP+ needs 100 domains vs 334 domains for Microsoft/Google. That's $3,040 saved on domains alone every year.

SMTP+ Questions

What are SMTP+ inboxes?
SMTP+ inboxes run on Amazon AWS infrastructure with US-based IPs. They connect to your sending tool via SMTP credentials — no OAuth, no tokens, no two-factor. Just paste the credentials and start sending.
Why are they so much cheaper?
We use AWS infrastructure instead of Microsoft 365 or Google Workspace licenses. Lower infrastructure costs = lower prices. The quality and deliverability are comparable.
Can I access the inbox natively?
Yes. Native inbox access is available for reading replies and managing your inbox directly.
What if an inbox gets burned?
Replace it for free. Swap the IP, swap the domain, or swap the username — all at no cost.
How many emails can I send per day?
We recommend 10 emails per day per inbox during warm-up and scaling. With 10 inboxes per domain, that's 100 emails per day per domain.
Do I need to bring my own domains?
You can bring your own or purchase domains through our platform. We handle all DNS setup either way.
Is the setup done for me?
Yes — full done-for-you DNS setup including SPF, DKIM, DMARC, and MX records. We also connect the inboxes to your sending tool.

Scale cold email for $1/inbox/mo

Microsoft IPs via AWS. 2-day warm-up. No OAuth. No disconnects. Free swaps. Just results.

Done-for-you DNS setup included. No credit card required to sign up.