Best for · 2026
Best private SMTP inboxes for cold email
Private SMTP inboxes run on the provider's own mail servers instead of Google or Microsoft. They are usually the cheapest per inbox and scale to thousands of inboxes; deliverability depends on how the provider manages IPs, warm-up and replacement.
Included if the vendor confirms on its site: private SMTP inboxes. Ordered by overall score.
Inbox providers 21
| # | Provider | Where the points come from | Score | Per inbox |
|---|---|---|---|---|
| 1 |  MailOptimalGoogle · Microsoft · SMTP |
83 | $2/inbox$1 at volume | |
| 2 |  Outreach2daySMTP |
77 | $2.50/inbox | |
| 3 |  MailDeckGoogle · Microsoft · SMTP |
76 | $0.60/inbox$0.40 at volume | |
| 4 |  IcemailGoogle · Microsoft · SMTP |
73 | $2.50/inbox | |
| 5 |  SkySendersSMTP |
62 | $2.95/inbox$2.69 at volume | |
| 6 |  SmtpfoxSMTP |
61 | $1.63/inbox$1.49 at volume | |
| =7 |  MaildosoSMTP |
60 | $2.50/inbox$0.49 at volume | |
| =7 |  ScaledMailGoogle · Microsoft · SMTP |
60 | $0.94/inbox | |
| =7 |  Sender PoolsGoogle · Microsoft · SMTP |
60 | $40/mo | |
| =7 |  WinnrSMTP |
60 | $1.38/inbox$0.95 at volume | |
| 11 |  AerosendSMTP |
59 | $4/inbox$2 at volume | |
| =12 |  MailpoolGoogle · Microsoft · SMTP |
56 | $3/inbox$2.60 at volume | |
| =12 |  OSDomainsGoogle · Microsoft · SMTP |
56 | $3.38/inbox$1.97 at volume | |
| 14 |  MailforgeSMTP |
45 | $3/inbox$2.40 at volume | |
| 15 |  InfraforgeSMTP |
43 | $4/inbox | |
| 16 |  Mission InboxSMTP |
40 | $3.33/inbox | |
| 17 |  Diamond MailGoogle · Microsoft · SMTP |
39 | $4.99/inbox$3.99 at volume | |
| 18 |  Deliveryman AISMTP |
37 | $49/mo | |
| 19 |  MailscaleSMTP |
34 | $5.27/inbox$1 at volume | |
| 20 |  MailreefSMTP |
33 | $249/mo | |
| 21 |  wizeMailsGoogle · SMTP |
26 | $22.38/inbox$18.09 at volume |
Deliverability 27Inbox choice 16Sending 15API & AI 7Buying terms 10Setup cost 25
Each bar is the score split by group (group weight in grey). Score out of 100 from conditions confirmed on the vendor's own site, plus up to 25 points for the cost of a 30-inbox setup. Prices shown: monthly billing, smallest public package.
Cold email software 7
| # | Tool | Where the points come from | Score | From |
|---|---|---|---|---|
| 1 |  InstantlySequencer with built-in inboxes |
100 | $47/mo | |
| 2 |  SmartleadSequencer with built-in inboxes |
96 | $39/mo | |
| 3 |  SalesforgeSequencer with built-in inboxes |
88 | $48/mo | |
| 4 |  WoodpeckerSequencer with built-in inboxes |
86 | $39/mo | |
| 5 |  SmartReach.ioSequencer with built-in inboxes |
82 | $29/mo | |
| 6 |  Reply.ioSequencer with built-in inboxes |
81 | $59/mo | |
| 7 |  MailshakeSequencer with built-in inboxes |
69 | $29/mo |
Deliverability 40Workflow 30API & AI 15Buying terms 15
Each bar is the score split by group (group weight in grey). Score out of 100 from conditions confirmed on the vendor's own site. Prices shown: monthly billing, smallest public package.
Other lists: Google Workspace inboxes · Microsoft 365 inboxes · Warm-up included · For agencies · For AI agents · Software with inboxes · Try before you pay