The First Email to Potential Customers: Structure, Length, Follow-Up

Why does the first email so often decide the conversation?

At a trade show, a buyer showed interest. On the phone, a managing director said she would like to see documents. A customer recommended you to a colleague, who agreed that you could get in touch. In all these cases, the first email is the bridge between contact and conversation. Many of these bridges do not hold because the email is too long, wants too much or names no clear next step.

This piece asks: How do you write the first email to a potential customer so that it is read and answered and stays legally sound? To answer it, we first clarify the legal limit, because it determines when a first email is an option at all. Then I present a model from communication research that explains what an email can and cannot achieve. After that come structure, subject line, length and follow-up.

The first email does not have to convince. It only has to get the recipient to reply.

When are you allowed to send the first email at all?

The article Data protection in sales describes the rules in detail. Here is what matters most for the first email. Under Section 7(2)(2) of the German Act Against Unfair Competition (UWG), advertising by email without the recipient’s prior express consent is an unreasonable nuisance, and this applies to businesses too. Presumed consent, which can be enough for calls to business customers, does not suffice here.

In practice, this means a first advertising email to someone you have never been in contact with is generally inadmissible, even if it is polite, short and personal. In the channel traffic light from the article mentioned, it is red. The first email in the sense of this guide is therefore the first email after a contact in which the recipient agreed that you may follow up in writing.

Record the consent in the CRM: from whom, when and for what. If the recipient objects later, Article 21 of the GDPR applies and the address goes on a block list. This is not legal advice. For details and borderline cases, such as messages in professional networks, seek professional advice. Rules differ in some other countries.

The thinking model: what an email can and cannot achieve

Why do so many first emails fail? One answer comes from media synchronicity theory. It distinguishes two kinds of communication processes. In conveyance, someone passes on information that the recipient can process at leisure. In convergence, two sides develop a shared understanding, for example of what a problem is and whether a solution fits. Conveyance works well with asynchronous media such as email; convergence needs media in which statement and response follow each other quickly, meaning conversation, phone or video call.

Anders, Coleman and Castleberry (2020) compared this theory with two older models of media choice. They surveyed 160 buyers in the United States, many of them members of the purchasing association Institute for Supply Management, on seven-point scales about their preferences. For contact with salespeople, buyers used email most often (mean 6.55), ahead of phone and voicemail (5.74) and face-to-face meetings (5.12). For the first message from a new salesperson, they clearly preferred email. For conflicts, negotiations and getting to know each other, they preferred phone and conversation.

Of the three theories compared, media synchronicity explained the answers best. Buyers justified their preference for email by saying they can check information, forward it and answer at a convenient time. The authors also cite the warning that salespeople might use email to avoid uncomfortable calls and possible rejection. The study’s limits: a survey in the United States, where different rules apply to advertising emails, and self-reports rather than observed behavior.

This gives the first email a clear task. It should convey, not converge. It gives the recipient what they need to decide about a conversation and proposes that conversation. Whoever tries to conduct the entire sales conversation in the first email overloads the medium.

The structure: five parts, one question

A structure follows from the model, which I call occasion, relevance, proof, question, complemented by a signature that makes the sender verifiable. Each part has a task, and none may be missing.

1. Subject line

   Names the occasion or topic in a few words, for example “Documents on maintenance planning, as discussed at the trade show”. No advertising promise, no capital letters.

2. Occasion

   The first sentence recalls the contact: where, when, about what. That way the recipient knows immediately why they are receiving this email.

3. Relevance

   Two or three sentences on the recipient’s situation and on what you can contribute. Their situation first, your service afterwards.

4. Proof

   One sentence with verifiable proof, such as a similar customer with name and result or an attached case study.

5. Question

   A single, easy-to-answer question with a concrete proposal, for example two time slots for a 20-minute conversation.

The sentence “Please do not hesitate to contact me with any questions” is the most common closing and the weakest. It leaves the recipient the work of inventing a next step. A concrete question takes that work off their hands. How the subsequent conversation should be structured is described in the article The first sales conversation.

Subject line and salutation: what a field experiment shows

A common piece of advice is to put the recipient’s first name in the subject line. It goes back to a much-cited study by Sahni, Wheeler and Chintagunta (2018), which found a markedly higher open rate using data from 2014. Defau and Zauner (2023) tested this with German-language emails in two field experiments with randomly formed groups.

In the first experiment, the first name appeared in the subject line, in the familiar form of address. This brought no advantage; the open rate was even slightly lower than without a name, but the difference was not significant. In the second experiment, a start-up asked local and regional politicians to take part in a survey. Here the subject line contained the formal salutation with Mr. or Ms. and surname. The open rate rose from 34.7 to 38.8 percent, an increase of almost 12 percent. For clicks, the difference was smaller and not significant.

The authors suspect that a once effective trick wears off when everyone uses it. For business customers in German-speaking countries, a cautious conclusion is that a formal, correct salutation works better than a familiar first name. However, the study concerns survey invitations, not sales emails, and the open rate is only an interim value. More important than any trick in the subject line is that the recipient recognizes the occasion immediately.

How long may the first email be?

Here too there are two readings. One says: as short as possible, because buyers have little time. The other says: detailed enough that the recipient can forward the email internally without having to explain what it is about. Both have a true core. The email itself stays short; everything else goes into an attachment or behind a link.

As a benchmark I set: the email can be read on a smartphone without scrolling, which is roughly 80 to 150 words. This is an assessment, not an established limit. It follows from the model: an email that conveys must be graspable in one pass. Whatever needs more space belongs in a case study, a proposal or a short video. When a video is the better complement is described in the article Video in B2B sales.

Following up: how often, at what interval, and when to stop

Many first emails go unanswered, not out of rejection but because they get lost in daily business. Following up therefore makes sense, provided consent to contact exists and there has been no objection. It needs a plan so that it is neither forgotten nor annoying.

1. First reminder after about four to five working days. Short, as a reply to your own email, with a new thought or something that makes it easier, such as a single proposed time.
2. Second reminder after about two weeks. With an open question as to whether the topic fits at the moment and the offer to get in touch later.
3. Then stop. The contact gets a follow-up date in the CRM in a few months, provided they have not objected.

How to assess replies afterwards and separate good inquiries from bad ones is described in the article Lead qualification.

The lesson beyond the case

The legal limit and the model of media synchronicity lead to the same result. Email is not a tool for generating contacts but for turning existing contacts into conversations. Whoever wants new contacts needs occasions: trade shows, talks, articles, referrals. How trade shows are used for this is described in the article Trade shows and events, how professional networks help in the article LinkedIn social selling.

The limits of this guide are clear. The studies cited come from the United States and from survey invitations, not from German sales emails. The benchmarks for length and intervals are assessments. What is established is the direction: emails convey well and converge poorly, and a correct, formal form of address does no harm with business customers in German-speaking countries.

Conclusion and next steps

The question was
the first email to a potential customer gets read and answered and stays legally sound. The answer: by resting on an occasion with consent, conveying instead of negotiating, staying short, ending with a single question and being followed up with a plan. Everything that needs convergence belongs in the conversation this email prepares.

• Check whether an occasion and consent are recorded for every contact on your list.
• Remove contacts without consent from the email list and plan another route.
• Write a template following occasion, relevance, proof, question, 150 words at most.
• Name the occasion in the subject line and use a formal salutation.
• Set up two reminders with fixed intervals as follow-ups in the CRM.
• Create a block list for objections that everyone in sales knows about.

The best first email is the one the recipient has been waiting for. The occasion ensures that, not the text.