SendboxPart of BoxSuite
updates

Updates

Everything we've shipped since Sendbox launched in September 2026, from the launch itself down to the smaller improvements that followed.

Releases
11
Months
2
Latest
October 2

Showing 11 of 11 releases

October 2026· 1 release

  1. IntegrationsNew

    Signed Webhooks, Easier to Verify

    Webhooks have been in Sendbox since launch. This release makes the signature side easier to work with, so your endpoint can confirm a payload really came from Sendbox before acting on it.

    Per-Endpoint Signing Secrets

    Per-Endpoint Signing Secrets

    • Every webhook endpoint gets its own secret key, managed from campaign settings
    • Each payload carries a signature generated from that secret, so you can reject anything that does not match
    • Covers all six events: lead.created, lead.added, lead.replied, lead.bounced, email.sent and email.opened
    • Point it at any HTTP endpoint: your own service, a CRM, Zapier, Make or n8n

    Webhooks are configured per campaign, so one client's pipeline never receives another client's events. The signature check closes the last gap: you know the request is genuine.

September 2026· 10 releases

  1. DeliverabilityNew

    Blacklist Monitoring on Every Domain and IP

    Landing on a blacklist is the kind of problem you usually find out about from a sudden drop in replies. Sendbox now watches your sending domains and dedicated IPs for you and flags a listing as soon as it shows up.

    Automatic Blacklist Checks

    Automatic Blacklist Checks

    • Sending domains and dedicated IPs are checked against the major blocklists on a schedule
    • A listing shows up as an alert in the dashboard next to the affected domain or IP
    • Mailboxes tied to a listed domain are easy to spot, so you can pause them before the next send
    • Included on every plan, with no per-check fees

    The point is simple: catch the problem before a campaign quietly fails, not after.

  2. AINew

    AI Reply Tagging in the Unified Inbox

    Replies from every connected mailbox already land in one unified inbox. Now each reply is tagged by intent as it arrives, so the people who want to talk are not buried under out-of-office notices.

    Intent Tags on Every Reply

    Intent Tags on Every Reply

    • Replies are sorted into tags such as interested, not interested, out of office, wrong person and meeting request
    • Filter the unified inbox by tag to work the most promising conversations first
    • Works alongside stop-on-reply rules, so a sequence halts the moment a lead responds
    • Pairs with the AI reply agent, which drafts a response using the full thread for context

    Less time sorting, more time answering the replies that can turn into meetings.

  3. DeliverabilityNew

    Inbox Placement Tests Across the Big Four

    Open rates do not tell you where an email landed. Inbox placement tests do. Send a test from any connected mailbox and see whether it reached the primary inbox, a tab, or spam.

    Placement Testing

    Placement Testing

    • One test covers Gmail, Outlook, Google Workspace and Microsoft 365
    • Results show inbox, promotions or spam per provider, not a single blended score
    • Run a test before a campaign goes live, or any time a mailbox starts to look off
    • Results stay attached to the mailbox so you can compare them over time

    If a mailbox is drifting toward spam, you see it here first and can pull it out of rotation before it hurts a campaign.

  4. DeliverabilityNew

    DNS Health Checks That Tell You What to Fix

    SPF, DKIM and DMARC are the first things inbox providers check and the easiest things to get slightly wrong. The domains page now runs a health check on every domain and explains any failure in plain language.

    SPF, DKIM and DMARC Checks

    SPF, DKIM and DMARC Checks

    • Each domain shows a pass, warning or fail for SPF, DKIM and DMARC
    • Failures come with the record Sendbox expected to find, so you know exactly what to change at your DNS host
    • Checks re-run automatically, so a record that breaks later gets flagged too
    • Domain status sits next to live mailbox status, so you can see which senders are affected

    A missing DKIM record should never be the reason a campaign lands in spam.

  5. DeliverabilityNew

    Warmup You Can Tune

    AI warmup runs automatically on every connected mailbox. This update gives you control over how fast it ramps, for teams who want to be more careful with brand new domains.

    Configurable Warmup Ramp

    Configurable Warmup Ramp

    • Set the starting daily volume and how quickly it climbs
    • Set a ceiling so warmup never competes with your live campaign sends
    • Pause and resume warmup per mailbox without losing progress
    • The warmup page shows each mailbox's current ramp day and today's warmup volume

    The defaults work for most teams. If you are warming a fresh domain and want to go slower, now you can.

  6. SequencerNew

    Sender Rotation and ESP Matching

    Campaigns can now spread sends across your mailboxes in the way that suits the campaign, and pair each lead with a sender on the same email provider.

    Rotation ModesESP Matching

    Rotation Modes

    • Choose round-robin, random or priority rotation per campaign
    • Each mailbox respects its own daily limit, so rotation never pushes one sender too hard
    • Mailboxes added mid-campaign join the rotation automatically

    Volume gets shared evenly, or weighted toward your strongest senders, without manual juggling.

    ESP Matching

    • Gmail leads can be sent from Gmail mailboxes, Outlook leads from Outlook mailboxes
    • Falls back to the normal rotation when no matching sender is available

    Provider-to-provider sending tends to land better, so Sendbox makes it a checkbox instead of a spreadsheet exercise.

  7. PlatformNew

    Free Deliverability Tools, No Account Needed

    Some deliverability questions should not require a sign-up. The free tools section offers quick checks anyone can run, whether or not they use Sendbox.

    Free Public Tools

    Free Public Tools

    • Blacklist checker, SPF/DKIM/DMARC checker and DNS lookup for domain and IP health
    • Email verifier, spam checker and subject line tester for copy and list quality
    • Warmup, mailbox, bounce rate and open rate calculators for planning volume
    • Email header analyzer, domain age checker and email signature generator

    Use them to sanity-check a setup before a campaign, or to work out whether a deliverability problem is DNS, reputation or copy.

    Open the free tools
  8. DataNew

    Email Validation Built Into Lead Import

    Bounces hurt sender reputation fast. Lead lists are now validated as they are imported, so bad addresses are caught before they ever reach a sequence.

    Validation on Import

    Validation on Import

    • Every address is checked when a CSV is uploaded
    • Invalid addresses are flagged and skipped, so they never enter a campaign
    • Included on every plan, with no per-address fee

    A clean list is the cheapest deliverability fix there is. Now it happens automatically.

  9. PlatformNew

    Dashboard Preview, Open to Everyone

    Not sure what you are signing up for? The dashboard preview lets you click through Sendbox with sample data before creating an account.

    Interactive Dashboard Preview

    Interactive Dashboard Preview

    • Browse the overview, mailboxes, domains, warmup, campaigns and billing pages
    • Sample data shows live mailbox status, DNS health, warmup progress and placement results
    • Nothing to install and nothing to connect

    We would rather show the product than describe it. The preview uses the same layout you get after signing up.

    Open the dashboard preview
  10. PlatformNew

    Sendbox Is Live: Public Launch

    After a private build and a small private beta earlier in 2026, Sendbox is open to everyone. It is cold email software built around one idea: your emails should reach the primary inbox, and nobody else's sending should be able to change that.

    Dedicated, Isolated InfrastructureCampaigns and RepliesPlans and Workspaces

    Dedicated, Isolated Infrastructure

    • Every customer sends from dedicated IPs on isolated sending infrastructure
    • Another customer's bad sending cannot drag down your reputation
    • Unlimited mailboxes: connect Gmail and Outlook through OAuth, or any provider over IMAP/SMTP
    • Automatic AI warmup, live mailbox status and domain management from day one

    Shared IP pools are one of the most common reasons good senders end up in spam. Sendbox does not put you in one.

    Campaigns and Replies

    • Multi-step sequences with A/B variants, auto-optimization, spintax and IF/THEN/ELSE branching
    • Timezone-aware sending windows and stop-on-reply rules
    • A unified inbox across every mailbox, with an AI reply agent
    • Signed webhooks for lead and email events, sent to any HTTP endpoint

    The sequencer covers what outbound teams expect. The difference is the infrastructure underneath it.

    Plans and Workspaces

    • Five plans: Launch, Growth, Scale, Fleet and Enterprise, with no per-seat pricing
    • Workspaces to keep teams or agency clients separate
    • White label on Scale and above, branded reports on Fleet and above
    • Phone dialer is on the roadmap and marked as coming soon

    Pricing scales with sending volume, not headcount, so adding mailboxes or teammates does not add surprise costs.

Land in the inbox.Not the spam folder.

Land in PrimarySee the Plans

Every plan includes dedicated IPs. No per-seat fees. Cancel whenever you want.