Warmup Inbox

Warmup Inbox is an email warmup service that builds sender reputation automatically so cold outreach and marketing campaigns land in the primary inbox instead of spam. Connected mailboxes exchange natural-looking messages with a network the company states exceeds 30,000 real human inboxes across more than 25 providers, producing genuine opens, replies, and mark-as-not-spam actions rather than scripted engagement. Alongside warmup it monitors inbox placement, spam and bounce rates, sender reputation, and DNS configuration, and checks more than 100 blacklists daily with automatic delisting when an inbox or domain is flagged. It connects to Gmail and Google Workspace, Outlook and Microsoft 365, Yahoo, Zoho, ProtonMail, Fastmail, iCloud, Amazon SES, Mailgun, SendGrid, and any provider that supports SMTP, and adds IP warmup, ESP-specific warmup, language warmup, and a cold email sequencer. The product is used by SDR teams, marketers, recruiters, and agencies, and holds a 4.6 out of 5 rating on G2 from 48 reviews.

Features

• Real-Inbox Warmup Network: More than 30,000 human inboxes exchange email with connected accounts, including opens, replies, and rescuing messages from spam folders.
• Deliverability Monitoring: Tracks inbox, spam, and bounce rates plus sender reputation and DNS records including SPF and DKIM, with alerts when metrics slip.
• Blacklist Rescue: Checks over 100 blacklists daily and runs an automatic delisting process when a domain or sending IP is listed.
• IP and ESP Warmup: Warms dedicated IPs before scaling and lets users concentrate warmup on a specific provider such as Gmail or Outlook.
• Language Warmup: Runs warmup conversations in the language of the target market rather than English only.
• Sequencer and Free Toolkit: Includes cold email sequences plus public tools for placement testing, DMARC and SPF generation, spam and blacklist checks, and reputation scoring.

Pricing

Warmup Inbox charges per inbox per month, with a seven-day free trial that requires no credit card. Annual billing saves 20%:

• Basic: $15 per inbox/month, or $180 billed yearly. 75 warmup messages per day, reply rates up to 25%, spam and category monitoring, reputation checks, outreach sequences, dashboards, and developer API.
• Pro: $49 per inbox/month, or $588 billed yearly. 250 warmup messages per day, reply rates up to 45%, custom templates and topics, language warmup, ESP-specific warmup, scheduled warmup, and priority support.
• Max: $79 per inbox/month, or $948 billed yearly. 1,000 warmup messages per day, reply rates up to 50%, premium support, technical setup check, unlimited API access, and early feature access.
• Agencies and teams: Contact for details. Custom plans start at 15 inboxes with larger discounts past 50, plus multi-client workspaces, white-label reports, and consolidated billing.

Plans can be upgraded or downgraded at any time with prorated adjustments, and inboxes added mid-cycle are billed pro rata from the day they are connected.

Pros

• Standout Customer Support: Reviewers repeatedly single out fast, knowledgeable chat support that walks them through setup and reputation recovery.
• Quick Setup: Users describe connecting an inbox and starting warmup within minutes, with several reporting visible improvement inside one to two weeks.
• Clear Per-Provider Reporting: Reviewers value reputation scores broken out by email provider and dashboards that show exactly where messages are landing.
• Affordable Against Alternatives: Multiple reviewers describe the pricing as noticeably cheaper than competing warmup tools doing the same job.
• Genuine Engagement Network: Users credit the network of real inboxes and automatic spam rescue with cutting spam placement significantly.
• Scales to Large Fleets: One customer reports running more than 1,500 mailboxes on the platform.

Cons

• Per-Inbox Cost Adds Up: Because pricing scales by mailbox, reviewers running many inboxes note the monthly total becomes substantial.
• Billing Can Confuse: Several reviewers describe plan structures and invoicing as initially unclear, and a minority report frustrating billing experiences.
• Occasional Connection Problems: Some users report SMTP or IMAP connection errors and warmup stopping unexpectedly, requiring support to resolve.
• Not a Full Outreach Suite: Reviewers note it covers warmup and deliverability rather than acting as a CRM or complete email marketing platform.
• Reporting and Support Limits: Older reviews mention weekday-only support hours and restricted historical reporting windows.
• Warmup Mail Needs Filtering: Users mention setting up filters to keep warmup conversations out of their working inbox.