SendCanyon · deliverability-first outbound

Cold email that lands
for founders.

Send from the mailboxes you already own. SendCanyon proves the domain, warms it properly, spreads the volume, and stops the moment somebody replies, so the work you put into the message is not wasted in a spam folder.

  • 14-day trial
  • No card required
  • Your mailboxes, your domains

Checked continuously on every domain and every send

SPFDKIMDMARC policyMX recordsBounce rateComplaint rateReply captureWarmup rampPer-domain daily capSuppression listUnsubscribesSend window
The workspace

One screen that tells you whether today went well

Campaign health, the sending window, and every mailbox in rotation, including the one that just took itself out.

Active
Sent this week0
Delivered0.0%
Replies0
Bounced0.0%
Sending window · 08:00-17:00312 / 400 planned today
Mailbox rotationToday · cap
  • ana@outbound.acme.co64 / 80
  • sam@mail.acme.co58 / 80
  • jo@acme.copaused

jo@acme.co pulled from rotation: bounce rate 4.1% over the last 200 sends

  • Google Workspace

    OAuth, no app password

  • Microsoft 365

    OAuth via Microsoft Graph

  • Any SMTP + IMAP

    Host, port, credentials

  • Amazon SES

    Your AWS account and quota

Google Workspace and Microsoft 365 over OAuth, any SMTP + IMAP server, or Amazon SES, with credentials verified before they are stored.

The system

The unglamorous work, running all day.

  • SPF, DKIM and DMARC resolved against live DNS, re-checked every 6 hours
  • 28-day warmup with opens confirmed on the receiving mailbox
  • Lists validated at import; suppressions re-applied before every step
  • Volume spread across the pool; degrading mailboxes step out alone
  • Replies read over IMAP or Graph; queued steps genuinely cancelled
  • SpirenAI drafts the sequence; nothing sends until you say so

The limits are the feature.

Four constants the pipeline enforces on every send, not settings you can raise until they stop protecting you.

0s

minimum gap between sends per mailbox

0

sends per domain per day, hard ceiling

0 days

warmup ramp for a new mailbox

0s

between reply checks on every inbox

Warmup

A ramp that is actually measured

New mailboxes climb to full volume over four weeks, exchanging real mail with real peer inboxes, and the open is confirmed by reading the receiving side, not assumed.

  • Starts at 5 sends a day
  • Campaign sending stays locked
  • Opens verified, not assumed
Warming · day 12
Daily send allowance

0 / day

28-day ramp
campaign sends unlockDay 1Day 28

Warmup mail goes to real peer mailboxes and the open is confirmed by reading the receiving inbox, not simulated.

Rotation and pacing

Nothing about the send log looks automated

Each mailbox waits at least 75 seconds between sends plus a random pause, under a hard per-domain ceiling. A mailbox that starts bouncing leaves rotation on its own.

  • Uneven, human-shaped intervals
  • Degrading mailboxes step out
  • Per-domain ceiling enforced
Sending
Ten minutes of a live send window16 sends
ana@outboundsam@mailben@mail00:0010:00

Each mailbox waits at least 75 seconds between sends, plus a random extra pause, so the pattern never looks machine-timed.

Replies

The only outcome that counts, handled first

Replies are read straight from the mailbox on a sixty-second tick and matched to the step that produced them, which is what makes stop-on-reply actually stop.

  • Read over IMAP or Graph
  • Matched to contact and step
  • Pending steps cancelled
3 new
  • Marta KowalskiInterested

    Interesting timing. We're re-tendering in October. Can you send pricing?

  • Daniel RhodesNot now

    Not right now, try me after the new financial year.

  • Aoife O'BrienAuto-reply

    I am out of the office until 3 September with limited access to email.

Replies are read from the mailbox itself over IMAP or Microsoft Graph, which is what makes stop-on-reply actually stop.

SpirenAI

The sequence drafts itself. You keep the pen.

Describe the offer, the audience and the tone. Up to five steps come back, and none of it sends until you say so.

SpirenAI · spiren-1

Your brief

ProductWarehouse routing softwareAudienceOps leads, 3PL, 50-500 staffToneDirectSteps3
Drafted three steps
  1. Your Rotterdam pick rateSends immediately

    Noticed you run three shifts out of one dock. Most 3PLs we…

  2. The 40-second versionWaits 3 working days

    Short follow-up with the one number that matters, no deck…

  3. Closing the loopWaits 5 working days

    One line, easy to say no to, leaves the door open for Q1…

AI credits this month184 / 250

Every draft opens in the editor. Nothing SpirenAI writes is sent until you send it.

Start sending from your own domains this week

Connect a mailbox, let warmup run while you write the first sequence, and watch every send in the log. 14 days free, no card.