What is Sendbox?

What Sendbox Does

Sendbox covers the whole cold email workflow, from building a campaign to watching deliverability in real time. Build multi-step sequences, split-test your subject lines and copy, work replies from a single unified inbox, and pull live analytics on every campaign you run. The part that sets Sendbox apart is underneath the surface: every plan sits on dedicated IPs and isolated infrastructure, which means another Sendbox customer getting blacklisted or sending spam simply doesn't touch your numbers.

Your sender reputation stays entirely in your hands.

How Sendbox Works

Connect your mailboxes (there's no cap on how many, on any plan), pull in or find your leads, put together your sequence, and send. Underneath, Sendbox hands your account dedicated IPs that nobody else touches. An AI-driven warmup process brings your accounts up to speed in a way built to get past email provider detection filters.

You get live reply and bounce numbers for every mailbox, which means a mailbox that starts to slip gets caught early enough to pull before it does real damage. Inbox placement testing tells you exactly where a send is going to land, primary, promotions, or spam, before you commit to sending it at scale.

Who Sendbox is For

Sendbox suits sales teams, agencies, and founders who depend on cold email for pipeline. If you've been burned before by deliverability problems tied to a shared platform, this is built to fix exactly that. Agencies get white-label branding and custom-branded reporting, which makes running several client accounts through one platform manageable.

It's a particularly strong fit for teams pushing past 10,000 emails a month who need infrastructure they can actually rely on.

The Infrastructure Difference

Most cold email platforms run everyone through shared infrastructure, meaning your emails leave from IP addresses that hundreds or thousands of other accounts also use. The moment one of them sends spam, that shared IP's reputation drops and your own emails start landing in spam right alongside theirs. It's the single biggest deliverability risk in cold email, and it's a risk you have zero say in.

Sendbox removes it outright: every plan gets dedicated IPs used only by your account, and your sending infrastructure never crosses paths with any other Sendbox customer. Email validation, inbox placement testing, blacklist monitoring, and AI warmup that gets past detection filters all come standard, with nothing held back as a paid extra.

Core Features

Everything a cold email operation needs lives in one place with Sendbox. That includes multi-step sequences with conditional branching and A/B testing, a unified inbox that pulls in replies from every campaign, a built-in dialer for calling leads without leaving the platform, AI reply tagging that sorts responses by intent automatically, and a native CRM with pipeline tracking. Webhooks come with HMAC signature verification for teams building custom integrations, and a CSV importer plus built-in lead finder round out prospecting.

On the deliverability side: inbox placement testing, blacklist monitoring, email validation, and warmup with no usage cap.

Pricing

Sendbox offers five plans, each scaled up for different sending volumes. Essential includes 75,000 emails, 30,000 leads, and 500 credits, with dedicated IPs built in from the start. Plus steps that up to 250,000 emails and 100,000 leads.

Pro unlocks 500,000 emails and unlimited leads. Agency layers on white-label branding, custom branded reports, and a dedicated account manager alongside 2,500,000 emails a month. Power scales to 10,000,000 emails.

No matter which tier you're on, dedicated IPs, unlimited email accounts, unlimited warmup, email validation, inbox placement testing, and blacklist monitoring are all included.

Compliance and Security

Compliance is designed into the platform rather than bolted on afterward. Sendbox handles CAN-SPAM and GDPR requirements through built-in unsubscribe management and data controls. Everything is encrypted both in transit and at rest, and your email account credentials are stored securely and never shared with anyone.

Key Features at a Glance