Deliverability playbook

Who this is for: anyone sending more than a few dozen emails a day, or anyone whose replies dropped and suspects spam folders.

Deliverability is whether your email reaches the inbox instead of spam. Mailbox providers judge every sending mailbox and domain on its history: how much it sends, how many messages bounce, how many people mark it as spam, and how many reply. This playbook turns that into settings.

The five rules

1. Warm up slowly. New mailboxes send little and grow week by week.
2. Keep volume per mailbox low. Scale with more mailboxes, not more volume per mailbox.
3. Protect your main domain. Send cold email from a separate domain.
4. Verify before you send. Bounces are the fastest way to lose reputation.
5. Write like a person. Short, plain, one question, no links in the first email.

1. Warm-up schedule

A suggested plan for each new sending mailbox:

Add 5 to 10 a day while replies keep coming in, and keep bounces under 2%.

Where to set it:

1. Settings > Sending accounts > edit the account > Daily sending limit (the account cap), Hourly limit and Wait between emails (seconds) (default 60).
2. In each campaign, wizard step 4 > Daily sending limit (the campaign cap, default 30).
3. Optional: Settings > Tracking and signature > Total daily limit (all accounts) caps the whole workspace.

The app sends the lowest of these. Raise the account cap as the mailbox ages.

2. Volume and pacing

• Wait between emails in the campaign (default 5-15 minutes) adds a random gap so sending looks human.
• Keep a Send between window in business hours. Send at any time of day works, but emails sent at night are more likely to be flagged as automated.
• Use Send on to skip weekends if your audience works Monday to Friday.
• After a pause, emails that were due are spread out again from the moment you resume, so a backlog never goes out in one burst.

Tip: Rough capacity per day = number of sending accounts x account cap, limited by the campaign’s daily limit and your window. Three mailboxes at 30 a day send up to 90.

3. Domains and mailboxes

• Register a second domain close to your brand for cold email and keep your main domain for customers and invoices.
• Set up SPF, DKIM and DMARC for every sending domain at your DNS provider. Your mail provider’s help pages show the records.
• Use a real person’s name in Sender name and a matching address.
• Add a signature with your name and company, and include an unsubscribe link (Settings > Tracking and signature, Insert unsubscribe link). Every campaign email also carries a one-click unsubscribe header.
• For tracked links, set a Tracking domain of your own (for example track.yourdomain.com) instead of a shared one.

4. Verification and list hygiene

1. Run the Email verifier on every list before its campaign.
2. In wizard step 4 > Email verification, leave Invalid unticked. Consider leaving Risky and Unknown unticked on a new mailbox.
3. Bounced and complaining addresses go on your suppression list automatically and are never emailed again.

The app protects you automatically. Once a campaign has sent at least 20 emails, it pauses itself when:

Resuming is your decision. Clean the list or rewrite the message first.

A sending account that fails 5 times in a row is switched off (Paused after errors) so it cannot keep failing. A sign-in failure marks it Not working at once.

5. Content

• 60 to 90 words. One idea. One question.
• No links, images or attachments in the first email. Ask for the call; send links after they reply.
• No spam words in the subject (free, guaranteed, act now), no all-caps, no exclamation marks.
• Personal and true: one real detail from their website beats three compliments.

The Prompt playbook turns these into instructions the AI follows.

Checklist before a big campaign

• Every sending account shows Working and has sent for at least two weeks.
• Account caps match their age (table above).
• The list is verified and Invalid is unticked.
• Review mode is on for the first batch.
• The window is business hours in the leads’ time zone.
• A reply inbox is connected, so replies stop outreach and bounces are caught.

Next step

Prompt playbook for high reply rates.