Guide

Email course ideas, and how to test one before writing

Last reviewed 21 September 2026

A good email course idea meets five conditions: it makes one promise, it is finished in five days, each day asks for something a reader can do before lunch, the reader can tell it worked, and you can write it from what you already know. The idea is almost never a new subject — it is the question you already answer most often, cut into five mornings. Everything below is that test, a table of ideas by the kind of work you do, and the shapes that reliably fail.

Most email courses are abandoned somewhere around day three of the writing, and the cause is nearly always the idea rather than the writing. An idea that was really a whole subject turns into a syllabus; an idea that was really a single blog post runs out after two mornings and gets padded; an idea that needed the reader to already own something they do not own produces a course nobody can act on. All three are visible before a word is written, which is what this page is for.

The five conditions an idea has to meet

A five-day course is a small container, and the whole art of choosing an idea is finding one that is the shape of the container rather than one that has to be squeezed into it. Five conditions decide that, and an idea that fails any of them is better fixed now than discovered on day three.

Run every candidate through these before writing anything:

  • One promise, stated in one sentence, in the reader’s words rather than yours. If the sentence needs an “and”, you have two courses and should pick the one you can write better.
  • Finished in five days. There has to be a state the reader reaches at the end, and it has to be a real end rather than the point at which you stopped. A subject with no natural finish becomes a newsletter, which is a different thing entirely.
  • One action a morning, small enough to do before lunch. A course that asks for an hour on day one has a completion rate of almost nothing, however good the email asking for it was.
  • The reader can tell it worked. Something visible by the last day — a photograph, a page, a decision made, a habit five days old. An idea whose payoff arrives in six months cannot be felt inside the course.
  • You can write it from what you already know. If the course requires research you have not done, you will not finish it, and the version you would have written from experience was the better one anyway.

The idea is usually something you already repeat

People look for a course idea the way they look for a business idea, as though it has to be new. It does not, and new is actively unhelpful here: a course teaches something, and you can only teach what you have already explained enough times to know where people get stuck. So the search is not for a subject nobody has covered. It is for the thing you personally have said out loud most often.

Three places to look, all of them retrospective. The question you answer in every first conversation, which is the one you have already refined by repetition. The thing you re-explain because the obvious explanation does not work — that is the part where you know something the published advice does not. And the mistake you keep correcting, because a course built around one recurring mistake has a built-in structure: what people do, why it seems right, what it costs, what to do instead, and how to tell it is working.

The test for all three is whether you could deliver it without notes. If you could talk for ten minutes on the subject to somebody sitting opposite you, there is a course in it. If you would need to go and read first, there is an article in it, and writing five emails will feel like homework for exactly as long as it takes you to stop.

Ideas, by the kind of work you do

These are starting points rather than titles to copy, and the last column is the useful one. Every idea in this table has a way of going wrong, and in almost every case the wrong version is the one that puts your business at the centre and the reader’s five mornings at the edge.

One idea for each kind of work, with the way that idea usually goes wrong
The work you doThe courseWhy it worksWhere it goes wrong
PhotographerFive days to photographs of your own family you will actually printThe reader already owns the camera, and each day is one decision: light, distance, timing, background, what to do with the resultIt turns into a settings course for people who are shooting on a phone
CoachThe five questions I ask every new clientIt is the work itself, shown rather than described, and the reader answers each one for themselvesThe answers are withheld to force a call, which readers notice by day two
Counsellor or therapistFive evenings: a wind-down routine you will actually keepBounded, daily, and entirely about what the reader does rather than about a conditionIt drifts into treating something, which is not a thing to do by email
AuthorFive days inside the research that did not fit in the bookThe material already exists, and it is the part readers write to you aboutIt becomes five days of asking people to buy the book
Software company onboarding new usersFive days to your first real report, using your own dataEach day is one action inside the product and ends in something the user can seeIt becomes a feature tour in the order the features were built
Newsletter writerFive days to a newsletter you can write in an hourIt teaches the habit the reader came for, and the last day is their first issueIt is five days about your newsletter rather than about theirs
Course creatorThe first module of the paid course, in full and unabridgedProof rather than a promise, and the strongest argument you have for the restIt is cut down into a trailer, which advertises that the paid version is thin
Freelancer or consultantFive days to a rate you can say out loud without flinchingThe reader has a specific, uncomfortable decision and a deadline they set themselvesIt becomes a pricing theory lecture with no number at the end
AgencyAudit your own funnel this week, the way we audit a client’sThe reader finishes holding a document, which is the thing an agency usually sellsThe audit turns out to require the agency to run it
NonprofitFive days with the people your last donation reachedOne story a day, specific and small, with no ask until the endEvery day ends in a donate button, and the stories become the wrapper
Fitness or nutrition coachFive mornings, five breakfastsThe action is small enough to do before work, and it repeatsDay one asks for an hour in a gym, and day two is sent to nobody
Estate agentFive days to a house that shows well, one room a dayThe reader has a real deadline and a physical room to work in each morningIt becomes five days of local market statistics
DeveloperFive days: ship one small thing to productionEach day ends in a commit, which is the most checkable completion signal there isIt assumes a stack, an account or a budget the reader does not have
Online shopFive days of getting more out of the thing you already boughtIt is written for existing customers, which is where the margin already isIt is five discount codes with paragraphs around them
Membership or community ownerFive days inside the part of the community people stay forIt shows the room from the inside instead of describing it from outsideIt is a tour of the features rather than of the people
Teacher or tutorFive days of ten-minute practice, for the adult sitting beside the childThe adult holds the address and the ten minutes, so the course is addressed to the person who can actIt is written to the child, who should not be on a mailing list at all

Four shapes that carry an idea, and one that does not

Once you have a subject, the shape is a separate decision and it is worth making deliberately, because the shape determines what each of the five mornings contains. The walkthrough takes one thing from nothing to finished, one stage a day, and is the easiest to write because the order is given to you. The teardown examines one real example a day — a page, a photograph, a pitch, a piece of code — and works because specifics are more persuasive than principles and because you can see them.

The decision course takes one hard choice and spends five days making it: what the options are, what each one costs, what most people get wrong, how to test cheaply, and how to commit. It suits subjects where the reader is stuck rather than uninformed. And the five-mistakes course takes the errors you correct most often, one a day, which has the advantage that the reader recognises themselves on day one and the disadvantage that it needs a constructive ending or it is five days of being told off.

The shape that does not work is the survey: an overview of a field, in five parts, covering everything. It fails for a structural reason rather than a stylistic one. A survey has no state the reader reaches, so there is nothing to feel on day five; it cannot ask for an action, because the actions differ by section; and it is the shape that expands under writing, so day three arrives and there are eleven things left that all seem necessary. If an idea can only be described as “everything about X”, it is not yet an idea.

Four ideas that look good on the page and fail in the inbox

The first is the comprehensive one, which is the survey wearing a better title. It is seductive because it feels generous, and it is the single most common reason a course is abandoned halfway through writing. The fix is almost always to take the third section of the comprehensive course and make that the whole thing.

The second is the idea that needs something the reader does not have: a tool they have not bought, an audience they have not built, data they have not collected. Every day of such a course opens with a precondition, and a reader who fails the precondition on day one quietly leaves. The fix is to write the course that gets them to the precondition instead, which is usually the more valuable course anyway.

The third is the sales sequence in a teaching costume. It is recognisable by the shape of its days: each one introduces a problem and defers the answer, and the answer turns out to be a purchase. Readers identify it quickly, and the cost is not only the unsubscribes. It is that a course is the one lead magnet people voluntarily read for five consecutive days, and spending that on a pitch you could have made once is an expensive trade.

The fourth is the idea chosen because it ranks rather than because you know it. A course written from research reads like one, because the specifics that make teaching work are the ones you only have from doing the thing. The search-volume argument is also weaker than it looks here: the traffic arrives on the page, and what converts on it is the promise being unusually specific, which is easier to be about a subject you have lived.

Test the idea before you write five emails

Write day three first. Day three is where a weak idea shows: day one is easy because it is the introduction and day five is easy because it is the conclusion, and day three is the one that has to carry actual content with no scaffolding around it. If you can write day three in forty minutes without notes, the idea holds. If day three is a struggle, the course is going to be a struggle, and you have spent forty minutes finding that out instead of a fortnight.

Then say the promise to somebody out loud and watch their face. The promise is one sentence and it has to survive being spoken: “by Friday you will have X” is a test that most vague ideas fail audibly, because you will hear yourself adding qualifications to it. If you have anywhere to ask — a client, a group, ten people who already read you — ask which of two promises they would want, rather than whether they like the idea. People are agreeable about ideas and decisive about choices.

And count the mornings honestly. Write the five subject lines before writing any bodies, in order, as a list. Five subject lines that each describe a different, specific thing the reader will do that day is an idea that works. If two of them are variations of each other, or if one of them is “introduction”, the course is four days long and should be sold as four.

The idea is also the thing people are agreeing to receive

There is a legal edge to this that is worth knowing before you write the sign-up form rather than after. Under the GDPR, consent has to be specific and informed: Article 4(11) defines it as a freely given, specific, informed and unambiguous indication of the person’s wishes, and Article 7 puts the burden on you to demonstrate it. The ICO’s direct marketing guidance says the same thing in plainer language — people should be told what they are signing up for, by whom, and in enough detail to know what will arrive. The idea you choose is the content of that agreement.

This has a practical consequence that has nothing to do with regulators. A vague promise collects addresses from people who wanted something else, and people who wanted something else are where complaints come from. Google asks bulk senders to keep the spam complaint rate below 0.10 per cent and never to reach 0.30 per cent, which is three complaints per thousand delivered — a threshold a small list can cross with a handful of people who signed up for a subject they did not get. A specific idea is a smaller list and a much safer one.

The last consideration is what happens on day six. If the course exists to sell something, say so on the sign-up form rather than at the end, and be aware that the moment the primary purpose of a message is commercial advertising it is commercial email in the FTC’s sense, with the footer, the postal address and the opt-out obligations that follow. None of this narrows what you can teach. It narrows how vaguely you are allowed to describe it, which was worth doing anyway.

Common questions

What should my email course be about?

The thing you already explain most often. Look at the question you answer in every first conversation, the thing you have to re-explain because the obvious explanation does not work, and the mistake you keep correcting — all three are subjects you can teach without research, which is what makes a course finishable. Then check the idea against five conditions: one promise, finished in five days, one small action each morning, a result the reader can see by the last day, and writeable from what you already know.

How do I know if an email course idea is good enough?

Write day three before you write anything else. Day one is easy because it introduces and day five is easy because it concludes, so day three is where a weak idea shows: if you can write it in forty minutes with no notes, the idea holds. Then list the five subject lines in order. If each one names a different, specific thing the reader will do that morning, the idea works. If two are variations of each other, or one of them is “introduction”, you have a four-day course.

What kinds of email course ideas usually fail?

Four of them. The comprehensive survey of a subject, because it has no finish line, no daily action and expands while you write it. The idea that needs something the reader does not have — a tool, an audience, data — because every day opens with a precondition they fail. The sales sequence dressed as teaching, which readers identify by day two. And the subject chosen for its search volume rather than because you have done it, which reads like research because it is.

Does the course idea have to match what people signed up for?

Yes, and it is the same requirement from two directions. The GDPR asks for consent that is specific and informed, and puts the burden on you to demonstrate what each person agreed to, so the promise on the form is the scope of the agreement. Separately, a vague promise collects people who wanted something else, and those are the people who report mail as spam. On a small list a handful of them is enough to cross a complaint threshold, so precision in the promise is a deliverability decision as much as a legal one.

The short version: the idea is almost never new, it is the question you already answer most often, cut into five mornings that each ask for one small thing. Test it by writing day three before anything else, by saying the promise out loud, and by listing five subject lines that are genuinely different from one another. Avoid the comprehensive survey, the idea that needs something the reader does not have, the sales sequence in a teaching costume, and the subject you picked for its search volume rather than because you know it. And write the promise precisely, because the promise is what people are agreeing to receive.

Sources

  1. Regulation (EU) 2016/679, the GDPR, Articles 4(11) and 7 on consent, on EUR-Lex
  2. The ICO’s guidance on direct marketing, on what a sign-up has to make clear
  3. FTC: CAN-SPAM Act compliance guide for business, and its primary-purpose test
  4. Google’s email sender guidelines, which publish the spam complaint thresholds

Read next

This page is part of Email courses: how to write one people finish, which is the complete guide to the subject.

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