At SendIQ, we analysed more than 100,000 B2B emails across 15 industries to uncover what really works in today’s crowded inboxes. From fintech startups to established manufacturers, our study tracked open rates, click-throughs, response rates, and conversions — representing over £2.3 million in pipeline value.
These aren’t abstract marketing theories. This is real campaign data from January 2023 to September 2024, showing how British businesses are generating leads right now.
Subject Lines: Still the Gatekeeper
Our findings confirm that subject lines remain the single biggest driver of open rates.
- Personalised subject lines achieved 26% higher opens.
- The sweet spot length: 30–50 characters.
- Industry-specific terminology outperformed generic business language by 18%.
B2B buyers respond best when subject lines signal content immediately relevant to their sector.
Timing: When You Send Matters
Weekdays are not created equal.
- Tuesday afternoons (2–4 PM) generated 34% higher open rates than Monday mornings.
- Wednesday and Thursday consistently performed strongly across industries.
- Fridays, often overlooked, proved effective for follow-ups — response rates were 22% higher than initial outreach sent on the same day.
The data suggests buyers are more willing to engage with familiar senders as the week winds down.
What Works in B2B Email Outreach
Personalisation Beyond “Hi [First Name]”
Campaigns that referenced company-specific challenges, recent announcements, or industry-relevant case studies performed best. These emails achieved 43% higher response rates compared to templated outreach.
Social Proof with Substance
Including specific case study results or client metrics boosted click-through rates by 31%. Relevance is critical — manufacturing audiences, for example, engaged 67% more when shown examples from similar firms rather than generic testimonials.
Mistakes That Cost You Leads
Over-Aggressive Sequences
Follow-up cadence is a balancing act. Our study shows the optimal pattern is 3–7–14 days, with 4–5 total emails. Exceeding six touches led to diminishing returns and a 23% increase in unsubscribes.
Poor Mobile Optimisation
With 67% of decision-makers reading on mobile, campaigns not designed for small screens are losing traction. Mobile-friendly emails delivered 29% higher CTRs and 15% better conversions.
The essentials: short subject lines, single-column layouts, bold CTAs, and scannable copy.
Industry-Specific Takeaways
- Technology: Highest engagement overall — open rates 24.7%, responses 3.2% — but shortest attention spans. Concise messaging works best.
- Manufacturing: Slower to engage but more likely to convert, with 41% higher conversion rates once active. Nurture sequences are key.
- Financial Services: Compliance language matters. FCA-regulated firms responded 58% better when emails explicitly addressed regulation and risk.
Turning Data Into Action
The evidence is clear: success in B2B email isn’t about volume, it’s about precision. Campaigns that combine:
- Subject lines tailored to industries
- Strategic timing and cadence
- Meaningful personalisation
- Relevant social proof
- Mobile-first design
…consistently outperform the rest.
At SendIQ, we apply these insights across email, LinkedIn automation, cold calling, and website visitor identification to help UK businesses build stronger pipelines.
