Connect every mailbox you need. Warmup handles itself.
Add Gmail, Outlook, or any provider that speaks IMAP/SMTP. Once connected, warmup kicks off in the background on its own, you set the volume targets and reply-rate goals, Sendbox does the rest. DNS health checks continuously confirm your SPF, DKIM, and DMARC records are configured correctly.
Mailboxes
Outreach
Link your inboxes
Add Gmail or Outlook through OAuth in a couple clicks, or hook up any other provider with IMAP/SMTP credentials. Google and Microsoft users skip the app-password hassle entirely.
- No cap on accounts
- Warmup that runs itself
- DNS health checks
- Live mailbox status
A look inside the Sendbox dashboard, where Mailboxes lives.
Mailboxes
Email | Status | Sent / Limit | Tags | Warmup Stats | Warmup | Sending | |
|---|---|---|---|---|---|---|---|
jordan@brightloop.com Jordan Reyes | Active | 22/50 | Cold Outreach | Day 1920/3088% health | |||
maya@brightloop.com Maya Torres | Active | 27/50 | Cold Outreach | Day 1516/3082% health | |||
pool@deskflow.io Outbound Pool | Active | 6/20 | Warming Pool | Day 910/3071% health | |||
jordan@seconddesk.io Jordan (Domain B) | Active | 33/50 | Cold Outreach | Day 2223/3090% health | |||
team@coldrelay.com Growth Team | Active | 45/55 | Agency | Day 2727/3096% health | |||
leah@fourthdesk.io Leah Nakamura | Active | 14/45 | Cold Outreach | Day 1011/3075% health | |||
sam@outreach.agency Sam Whitfield | Active | 39/50 | Agency | Day 2323/3089% health | |||
maya@signalwarm.io Maya (Warm Pool) | Active | 4/20 | Warming Pool | Day 45/3060% health | |||
noah@fourthdesk.io Noah Bennett | Active | 31/50 | Cold Outreach | Day 1718/3085% health |
One connection, indefinite sending
No cap on accounts
Connect as many mailboxes as you like, Gmail OAuth, Outlook OAuth, or custom IMAP/SMTP, with nothing charged per seat.
Warmup that runs itself
Background workers operate continuously against the starting volume, daily ramp, target, and reply-rate goals you configure.
DNS health checks
Every connected mailbox gets its SPF, DKIM, and DMARC records validated, so configuration problems surface before they hurt sending.
Live mailbox status
Each mailbox reports its current state, active, inactive, error, warming_up, suspended, or failed, so you always know where things stand.
Step 1
Link your inboxes
Add Gmail or Outlook through OAuth in a couple clicks, or hook up any other provider with IMAP/SMTP credentials. Google and Microsoft users skip the app-password hassle entirely.
Step 2
Warmup kicks off without you
Background workers cycle every 5 to 30 seconds. Set your starting volume, how fast it should ramp, the target volume, and your reply-rate goals, then step back. Warmup just happens.
Step 3
Put it to work in a campaign
Choose which mailboxes send for each campaign and pick a rotation mode, round-robin, random, or priority. Sendbox honors each account's daily limit and matches ESPs where it can.
Where it fits
Agencies running high volume
Connect as many mailboxes as your client roster needs, across as many domains as you want. Rotation spreads the load so no single account carries too much.
Warming a brand-new domain
Define your starting volume, daily ramp, and target, then let the warmup workers take it from there while you build out campaigns in the background.
Running Gmail and Outlook together
Mix Gmail and Outlook mailboxes inside a single campaign. ESP matching sends Gmail leads through Gmail senders and Outlook leads through Outlook senders automatically.
Every mailbox gets its own dedicated IP
Warmup that runs itself, DNS checks that catch problems first
Too many tools treat warmup as a switch you flip and forget. Sendbox's background workers check in every 5 to 30 seconds against the volume and reply-rate targets you set, while continuous SPF, DKIM, and DMARC validation flags a misconfigured record before it wrecks your sending reputation.
- Beats Instantly
- Beats Smartlead
Warmup with real dials to turn
Set your starting volume, how fast it ramps daily, the target volume, and your reply-rate goals.
- Background workers handle execution, cycling every 5 to 30 seconds, and vary activity naturally so it doesn't read as automated to email providers.
Three ways to rotate senders
Assign several mailboxes to one campaign and choose how sends get distributed: round-robin spreads evenly, random keeps it unpredictable, priority lets you favor specific senders.
- ESP matching routes through the right provider whenever it can.
As many as you want, there's no cap tied to your plan. Connect five or five hundred.
Ready to land in primary?
Get your own isolated Sendbox setup running and start sending inside 15 minutes.
Every plan includes a dedicated IP. Cancel whenever you want.
