LinkedIn InMail is a paid message you can send to a LinkedIn member you are not connected to, using credits that come with Premium, Sales Navigator or Recruiter plans. A regular message only goes to your first-degree connections (and a few exceptions like Open Profiles). InMail is useful for recruiting and for reaching a specific person you have no other route to. For founders selling, it works far better when the recipient already recognizes your name from your posts and comments.
LinkedIn InMail is a message you pay to send to someone outside your network. You don't need to be connected, you don't need their email, and it lands in their LinkedIn inbox flagged as InMail. You get a monthly allowance of InMail credits with paid plans like Premium, Sales Navigator and Recruiter, and the number depends on the plan.
That's the definition. The more useful question is whether you should use it. I've spent a lot of time mapping go-to-market options for my own company, sitting with sales teams, SDRs and founders who all wanted pipeline from LinkedIn. My short answer: InMail is a fine tool for a narrow job, and a poor substitute for being someone the recipient has already heard of.
What is LinkedIn InMail, exactly?
InMail is LinkedIn's premium messaging feature. Here's what matters in practice:
- Who you can reach: any LinkedIn member, including second- and third-degree connections and people completely outside your network, unless they've turned InMail off in their settings.
- What it costs: credits. Each plan includes a monthly number of InMail credits. LinkedIn has adjusted these numbers over the years, so check your own plan's page rather than trusting a blog post (including this one).
- Refunds: LinkedIn has long credited back InMails that get a response within a set window (90 days at the time of writing). A message that's ignored uses the credit.
- Where it shows up: in the recipient's normal LinkedIn inbox, labeled as InMail or sponsored, depending on the type.
There are a few other flavors people confuse with InMail. Open Profile messages go to Premium members who've chosen to let anyone message them for free, and they don't use a credit. Sponsored Messaging (sometimes called Message Ads) is a paid ad format bought through Campaign Manager, sent at scale. And recruiters get their own InMail pool through LinkedIn Recruiter.
InMail vs message: what's the difference?
This is the part most people actually search for, so here it is in one table.
| Regular message | InMail | |
|---|---|---|
| Who you can send to | 1st-degree connections (plus shared group members and Open Profiles) | Almost anyone on LinkedIn |
| Cost | Free | Uses a paid credit |
| Subject line | No | Yes |
| Length | Long (LinkedIn allows several thousand characters) | Shorter body limit, see below |
| How it feels to the recipient | A note from someone they accepted | A note from a stranger |
The last row is the one that decides your results. A regular message goes to someone who, at some point, clicked "accept." They know your name. An InMail is by definition a message from outside their network. The format tells them you're a stranger before they read a word.
A middle route sits between the two: the connection request with a note. It's free, it's short, and if they accept, you can send a normal message afterwards. In my experience, most founders use this far more than InMail.
InMail character limit and how to write one
At the time of writing, LinkedIn gives InMail roughly 200 characters for the subject line and about 1,900 characters for the body. The compose box enforces it, so you'll know if you go over. If you want to draft offline and check length first, the character counter does it.
My advice is to use a fraction of that. Nobody wants 1,900 characters from a stranger. What works in a cold message is the same thing that works in a good post: say one specific thing, early.
- Subject: a reason that's about them. A post they wrote, a problem their role has, a shared context. Skip "Quick question."
- First line: why them, specifically. If you can't write this line honestly, don't send the message.
- The point: one sentence on what you want and why it's worth their time.
- The ask: small. A reply, a yes or no, a link. Asking a stranger for a 30-minute call in the first message is a big ask.
And before you hit send, look at your own profile the way they will. A stranger's InMail gets a profile click before it gets a reply. If your headline and About section are vague, the message dies there. The profile checker is a fast way to see what they'll see.
LinkedIn InMail response rate: what to expect
I'll be honest about what I don't know. I haven't found a current, reliable public benchmark for InMail response rates. You'll see numbers quoted all over the internet, from low single digits to "three times email." Most of them are old, from vendors selling something, or both. I'd ignore them.
What I'd do instead is measure your own. Response rate is simply replies divided by InMails sent, tracked for at least a few dozen messages before you draw any conclusion. Then change one thing at a time.
What I can tell you from my own calls is what moves that number. The biggest variable is whether the person has seen you before. Copy matters much less.
Here's a story from the commenting side of my work. An SDR team I talked to pushed back when I suggested they comment on their prospects' posts before reaching out. Their line was: "We are measured on outbound, not inbound." Fair. That's how they're paid. A couple of weeks later one of the reps tried it anyway, commenting on prospects' posts before his outreach. He told me his response rate doubled. Same rep, same product, same kind of message. The only change was that his name wasn't new anymore when the message arrived.
That's one rep's result. It also matches everything else I've seen.
Why cold InMail loses to warm inbound
When I sat down to map our go-to-market, I split the people downloading the product into groups. Two of them taught me the most about outbound versus inbound.
Sales teams live on attribution. The way sales and marketing teams think is the way they're measured. If a tactic can't show a line to booked meetings, it doesn't survive. I had one SDR who was a genuinely heavy user. He saw his profile views and search appearances going up. But he couldn't tie them directly to meetings booked, so he stopped. I also watched a head of sales, told by the CEO to try it, generate fewer than ten comments and quit.
InMail looks great under that lens. You send one, you get a reply or you don't, and the credit system even tells you the count. It's clean attribution. That's why sales teams like it.
Founders want something that compounds. The founders I talked to, especially early-stage ones, were mostly interested in building an inbound pipeline and a reputation. That's harder to measure, and it's what actually changes the economics. A cold InMail is a one-shot. You spend a credit, and if they don't reply, you have nothing. A post or a thoughtful comment keeps working. Someone reads it this week, someone else sees it next month, and the next time you message either of them, you aren't a stranger.
Here's how I'd compare them:
| Cold InMail | Warm inbound from posting and commenting | |
|---|---|---|
| Attribution | Clear, per message | Fuzzy, spread over weeks |
| Cost | Credits, every time | Your time (or a tool's) |
| Compounds | No | Yes |
| First impression | A stranger asking for something | Someone whose thinking they've seen |
| Scales with | Budget | Consistency |
The trap is choosing the clean attribution because it's easy to report, and then wondering why the reply rates are thin.
When LinkedIn InMail is actually worth it
I don't think InMail is useless. It's the right tool when:
- You're recruiting. Candidates expect recruiters to reach out cold, and the context (a job) is obvious. This is what InMail was built for.
- There's one specific person and no other route. A journalist, an investor, a potential partner. One well-written, specific InMail beats waiting.
- You've already warmed them up. They've reacted to your posts or you've been in their comments, but you aren't connected yet. InMail becomes a follow-up rather than a cold open.
- They have an Open Profile. Then it's free, so the math is easy.
Where I'd skip it: blasting a list. If your plan is to send InMail to everyone who matches a title filter, you're paying to be the stranger in their inbox, at scale.
A better sequence: post, comment, then message
The sequence I recommend to founders flips the order most people use.
- Post about the problem your buyer has. One agency owner who builds LinkedIn inbound systems walks clients through a content plan by awareness stage: people who don't know they have the problem, people who know the problem, people comparing solutions, and people who already know your product. It's a good framework. It's also a lot of work to adapt to your own business, which is exactly why most founders never do it.
- Comment where your buyers already are. A good comment on a prospect's post puts your name in front of them in a context they chose. I wrote more on why in commenting is the highest-leverage, lowest-status thing you can do on LinkedIn.
- Then reach out. A connection request with a short note, or a regular message if you're already connected. Save InMail for the people you can't reach any other way.
This is what social selling looks like when it works. By step three, you're sending the same message you would have sent cold. It just lands differently, because they've already seen what you think.
This is the part of the system I built Liftli around: the posting and commenting that make step three work. You can do all of it by hand, and many founders do. The point is that the cold message is the last step, and it only works as well as everything that came before it.
There's one more thing I've learned about founders, from the go-to-market analysis. They want the reputation, and they usually don't want to spend the time. That's why ghostwriting agencies with a fire-and-forget model do well, and it's why InMail is tempting: it feels like a shortcut. It isn't one. The founders I've seen get real inbound are the ones who stayed hands-on with their own voice, even for ten minutes a day. You can't lead what you've never touched, and you can't sell as a stranger when you could have been a familiar name.