A double opt-in introduction is the practice of confirming interest from both parties before completing a warm introduction. The connector pings the requester and the target separately, gets a clear yes from each, then sends the intro email. The pattern originated in venture capital (Brad Feld's "forward this email" technique is the canonical reference) and is now standard etiquette in B2B sales, recruiting, and executive networking. Double opt-in protects everyone's time, preserves the connector's reputation, and dramatically increases the response rate on the actual intro email.
How a double opt-in introduction works (the 4-step pattern)
| Step | What happens | Who's involved |
|---|---|---|
| 1. Request | Requester asks the connector for an intro to the target. Includes context: why they want to meet, what's in it for the target, and a short forwardable blurb. | Requester → Connector |
| 2. Opt-in ping | Connector emails the target with the requester's blurb and asks, "Worth an intro?" The target says yes or no — or not now. | Connector → Target |
| 3. Bridge intro | If the target says yes, the connector emails both parties with context and explicit handoff: "You two should connect. I'll let you take it from here." | Connector → Requester + Target |
| 4. Reply | Requester replies first with a substantive message anchored in the connector's framing. Target responds. Connector is removed from the thread. | Requester ↔ Target |
Why double opt-in beats forwarded intros
The alternative — sending the intro email without confirming with the target — is called a "single opt-in" or just a forwarded intro. It feels faster but creates four problems:
Connector reputation risk. If the target is annoyed by the intro, the connector takes the blame. Repeat this 10 times and connectors stop accepting intro requests.
Wasted time. If the target wasn't going to engage, the requester spent effort drafting a message no one wanted.
Lower response rate. Cold-feeling intros (even when warmed by a connector) get ignored if the target wasn't primed.
Awkward decline. The target has to either ghost the requester (bad) or write a polite no after the fact (worse).
Double opt-in solves all four. The cost is one extra email and 24-48 hours of latency. Worth it.
The Brad Feld template (canonical)
Most VCs run a version of this template for the opt-in ping:
Subject: Worth an intro?
Hey [Target],
I got the request below from [Requester]. He/she is [one-sentence credibility — "the founder of X," "running BD at Y"]. The ask: [one sentence].
Worth an intro? No worries either way. If yes I'll loop you both in. If not just say no and I'll close the loop.
— [Connector]
If the target says yes, the connector then sends the bridge intro:
Subject: [Requester] meet [Target]
[Requester] — [Target] is [credibility line — "VP Sales at X," "my former colleague at Y"]. [Target] knows your space well and was happy to chat.
[Target] — [Requester] is [credibility]. They're working on [project / context]. The ask is [one sentence].
I'll let you two take it from here. Both worth knowing.
— [Connector]
When to use double opt-in
Always, with three exceptions:
Pre-arranged intros. If the target already told the connector "introduce me to anyone in cybersecurity," the opt-in is implicit. No need to re-confirm.
Reciprocal exchanges. If two people both asked the connector to introduce them to each other, skip the opt-in.
Inside the same company. Cross-functional intros where the target's job is to take meetings (e.g., "meet our new VP Sales") don't need opt-in.
Every other case, run the double opt-in.
Where double opt-in shows up in B2B sales
In sales, double opt-in is the gold standard for high-value warm intros:
- Customer-to-prospect intros. The CSM asks the customer to intro the rep to a peer at another company. The customer confirms with the peer before sending.
- Investor-to-buyer intros. The CEO asks a board member to intro the rep to a CRO at a portfolio company. The board member confirms with the CRO first.
- Advisor-to-target intros. A C-level advisor confirms with their peer before the bridge.
Reps who skip double opt-in burn the connectors over time. Reps who insist on it preserve the relationship asset.
How tooling supports double opt-in
Modern relationship intelligence platforms automate the double opt-in flow:
- Bridge (brdg.app) built its product around it — IntroLinks send the opt-in ping automatically and the bridge intro auto-sends from the connector's inbox once the target confirms.
- Boomerang drafts the opt-in ping in the connector's voice, routes it for one-click approval, then drafts the bridge intro when the target confirms. The connector approves both, but doesn't write either.
- Trusio uses a structured "written requirements" form that the requester fills out, the connector reviews, and the target opts into.
The pattern is too valuable to be manual. If you're running 20+ warm intros a month, tooling that runs the double opt-in flow saves hours and preserves quality.
Common mistakes
Burying the ask. If the opt-in ping doesn't make the ask crystal clear in 2 sentences, the target says no by default.
Asking for too much. Double opt-in works for "15-min intro chat." It doesn't work for "I'd like 90 minutes to review our architecture." Big asks belong in the second email after the intro.
Forgetting to close the loop. If the target says no, the connector should tell the requester (gently) so they can move on. Ghosting damages the connector's reputation.
Skipping it for speed. The 24-hour delay is annoying. Burning the connector's credibility is worse.
Bottom line
Double opt-in is the etiquette that lets warm intros scale. Skip it and connectors stop helping. Run it well and your intro acceptance rate stays at 60-80%.
For the broader category, see warm introduction software and intro tracking and analytics.
