Cold Outbound Email Done Compliantly: A B2B Guide (2026)

#01What is the legal position by market?

See Email compliance: GDPR, PECR, CAN-SPAM and CASL for the wider picture. Practical steps:

• Map recipients by country before building a sequence; exclude high-risk markets or switch them to other channels.
• Document your legitimate interests assessment for EU and UK prospecting.
• Tell people where you got their data in the first email or privacy notice, as GDPR transparency rules require.
• Never buy lists with unknown provenance.

#02How do you protect your main domain?

Your primary domain carries invoices, password resets, product updates and newsletters. Cold email produces more complaints and bounces than opted-in email. Practitioners therefore separate them.

Separate domains reduce the blast radius but do not hide behaviour. Mailbox providers can still connect related domains, and recipients see your brand. Treat them as a safety margin, not a licence.

How much volume per inbox?

Hitting the official caps will trigger suspensions and almost certainly complaints. Practitioner volumes are deliberately far lower.

#03What makes cold email relevant?

1. Tight list: a defined segment (role, company size, trigger) with a specific reason to contact.
2. Trigger or insight: a public event (new finance leader hired, ERP migration announced) or a genuine observation.
3. Short message: under about 120 words, plain text, one ask.
4. Low-friction ask: "Worth a look?" or a resource, not a 45-minute demo.
5. Personal sender: a real person whose title fits the recipient.
6. Few follow-ups: two or three, spaced several days apart, each adding something.
7. Easy opt-out: a plain line such as "Not relevant? Reply 'no' and I won't email again", plus a link if you send at volume.

Template

Subject: Approvals during your NetSuite move

Hi Priya,

Saw that Northwind is moving to NetSuite this quarter. Teams in that spot often find invoice approvals get stuck between the old and new systems for a few weeks.

We wrote a 2-page checklist on keeping approvals moving during an ERP switch. Want me to send it?

Sam Patel
Ledgerline, 1 Example Street, London
Not relevant? Reply "no" and I won't follow up.

#04How do tools fit in?

Cold email platforms (Competitor A and Competitor B, for example) handle multiple inboxes, sequences, warm-up, rotation and reply detection. Use them for:

• Scheduling and throttling within the volumes above.
• Pausing a sequence automatically when someone replies.
• Central suppression across inboxes and domains.

Do not use them to:

• Send to scraped lists with no relevance check.
• Rotate dozens of domains to outrun complaints.
• Fully automate AI-written messages without a person reviewing who gets them.

A named person should approve each list and sequence, read replies and handle objections.

#05How do you handle opt-outs and complaints?

• Suppress immediately on "unsubscribe", "remove me", "not interested" and similar replies, across every tool, domain and CRM.
• Sync suppressions with your marketing ESP so the person does not later receive newsletters without consent.
• Watch complaint signals: Postmaster Tools spam rate, replies like "spam", sudden drops in replies.
• Stop and fix when bounce rate rises above about 2 to 3% per send (practitioner guidance): verify the list.

#06Worked example: Ledgerline

Ledgerline is a fictional accounts-payable software company. Figures are illustrative, not benchmarks.

Ledgerline's SDR team sends cold email from the main domain at 300 emails per rep per day. Postmaster Tools shows the spam rate rising and newsletters landing in spam.

Walkthrough

1. Stop: outbound paused from the main domain.
2. Legal map: German recipients removed; UK sole traders excluded; legitimate interests assessment documented.
3. Domains: two related outbound domains with SPF, DKIM, DMARC and redirects; five named inboxes per domain.
4. Warm-up: four-week ramp to about 40 new emails per inbox per day (practitioner guidance).
5. Lists: triggers only (finance leader hires, ERP migrations); fewer than 400 prospects a week (illustrative).
6. Copy: plain text, under 120 words, checklist offer, three steps max.
7. Suppression: global list shared with the ESP and CRM.
8. Result: main domain spam rate falls back below 0.1% over several weeks; reply rate on outbound rises (illustrative).

#07Common mistakes

• Sending cold email from the main domain.
• Ignoring country rules, especially in Germany.
• Buying or scraping lists without checks.
• High volumes per inbox.
• Opt-outs handled in one tool but not others.

#08Try it yourself

List the countries in your outbound targets and write the legal basis for each. Check whether outbound currently uses your main domain. Draft one plain-text cold email under 120 words with a trigger, a resource offer and an opt-out line.

#09Quick quiz

1. What does Google Workspace cap at 2,000 per user per day? Answer: Messages per user, and also unique external recipients. Total unique recipients are 3,000. Trial accounts are lower.

2. Why use separate outbound domains? Answer: So complaints and bounces from cold email do not damage the main domain's reputation.

3. Which market generally requires prior express consent for B2B email advertising? Answer: Germany (UWG section 7).

4. What should happen when someone replies "remove me"? Answer: Suppress them immediately across every tool, domain and the marketing ESP.

#10What should you check before the next lesson?

• Legal basis documented per market.
• Outbound off the main domain.
• Volumes per inbox within practitioner limits.
• Global suppression list in place.

Previous: UTM tagging and GA4 tracking for email · Next: AI writing, personalisation and AI inboxes

Or return to the Email Marketing for Marketers track.

Related: Email compliance: GDPR, PECR, CAN-SPAM and CASL · Domain warm-up and list hygiene · Sender requirements at Gmail, Yahoo and Outlook

#11Common questions

Is cold email legal? It depends on where the recipient is. In the US, CAN-SPAM allows it with honest headers, a postal address and a working opt-out. The UK allows it to corporate addresses with identification and an opt-out. Germany generally requires prior express consent even for B2B email advertising. Canada's CASL needs consent or a narrow exception. Take legal advice for your markets.

Should I send cold email from my main domain? Most practitioners use separate, clearly related domains for outbound so complaints do not damage the main domain that carries invoices, product email and marketing. Those domains still need full authentication and honest branding.

How many cold emails can one inbox send per day? Google Workspace caps a user at 2,000 messages a day, but that is a ceiling, not a target. Practitioners commonly keep cold volume to a few dozen emails per inbox per day to protect reputation.

Do Gmail's bulk sender rules apply to cold email? Yes. The requirements apply to all mail sent to Gmail addresses, with extra rules for senders above about 5,000 messages a day. Spam complaints from cold email count against your domain's reputation.