We analysed 6,337 cold emails students sent for internships. Here's what works in 2026
For the last 6 months we've been tracking what works in cold email outreach for internships. After analysing 6,337 emails sent by 200+ students between November 2025 and May 2026, a few patterns stood out clearly.
Subject lines:
- Under 30 characters: 83.7% open rate
- 70+ characters: 69.5% open rate
- Subjects containing a number open at 80.6% (highest pattern)
- Subjects with "interested in" open at 79.0%
Email body length (this one surprised me):
- Under 100 words: 11.9% reply rate
- 100-200 words: 1.9%
- 200-300 words: 0.3%
The 6x gap between under-100w and 200-300w surprised us. Most "good cold email" advice tells you to write 200-word emails. The data says shorter is better.
Follow-ups: A single follow-up lifts reply rates by 60%+. Peaks at 2 follow-ups (3 emails total). Past that, reply rates drop and unsubscribes spike.
Best send times (UTC): Wednesday > Tuesday > Sunday > Monday. Worst: Friday and Thursday. Best hours: 12:00, 15:00, 17:00. Avoid 09:00 and 14:00.
Who students actually email: Directors (2,944) and Managers (1,567) get 3x more outreach than CEOs and Founders combined. At firms over 50 people, the team Director is the hiring decision maker, not the CEO. Reply rates are way better when you email the actual hiring manager rather than going CEO-first unless the company is genuinely small.
Caveats I should be upfront about:
- Open rates inflated by ~30-40% due to Apple Mail Privacy Protection auto-opens (industry-wide, not specific to this dataset)
- Reply rates under-counted because we only see replies that come back to the connected mailbox (lots of replies go through other addresses, on phones, etc.)
Full breakdown with all the charts and methodology here: https://whali.co.uk/blog/cold-email-data-study-students-2026?utm_source=reddit&utm_medium=organic&utm_campaign=data-study&utm_content=rinternships
Happy to answer questions on methodology or specific findings.