ColdSire
ColdSire sells Google Workspace and Microsoft 365 mailboxes at a flat $6/mo per account, claiming deliverability advantage from housing cold-email accounts in a mixed-use infrastructure pool alongside real businesses.
Pricing breakdown
| Platform | Standard | Warmed | Volume |
|---|---|---|---|
| Google Workspace | $6.00 | — | — |
| Microsoft 365 | $6.00 | — | — |
Pricing notes
$6/inbox/mo; US-based Google Workspace
Our take on ColdSire
ColdSire keeps it simple: a flat $6/month per mailbox for both Google Workspace and Microsoft 365, set up in about five minutes. Its deliverability pitch is structural rather than warmup-based — it claims cold-email accounts make up only ~15% of its “premium mixed pool,” sitting alongside real businesses, which it argues improves placement.
The flip side is that $6 flat is at the premium end for what's offered, with no visible volume discounting, and no warming is included. The bigger consideration is maturity: the domain dates to late 2023, the company to 2024, and there are only around three Trustpilot reviews so far — a thin base to judge from. Several operational specifics (API, replacement policy, IP model and regions) are absent from public materials, so treat it as an early-stage option to test in small volume.
What we like
- +Flat, simple $6/mailbox for both GWS and M365
- +“Mixed-use pool” positioning (cold accounts a minority of infra)
- +Fast ~5-minute setup
Watch out for
- −Premium flat rate with no volume discounts shown
- −No warming offered
- −Very new (founded 2024) with only ~3 reviews so far
- −API, replacement and IP details undisclosed
Best for: Buyers who want dead-simple flat pricing for a small number of GWS/M365 inboxes and don't need volume discounts.