Email Marketing for Small Business in a LINE-First Market

When I was a kid, our house upcountry had a wooden letterbox nailed to the front fence. The postman came by on his motorbike once a day and dropped envelopes through the slot. Nobody ran out to open it. Some days a letter sat there until evening. Yet almost everything important reached our house that way: the electricity bill, bank statements, ordination invitations, letters from my aunt who worked in Bangkok. My mother read them, folded them and kept them in a drawer, and whenever she needed one, she could find it again.

Anything that couldn't wait never went through the letterbox.

Thai businesses today have the same two channels side by side. LINE OA is someone calling over the fence: you send, it pings, it's seen. Email marketing is the letterbox. It's slower and quieter, but it's where customers keep documents, search back through them and forward them to colleagues. Many owners ask me whether email marketing for small business still matters when every customer is already on LINE. In this article I'll answer honestly: when you don't need it yet, where email still does a better job, and what to set up so your emails actually land in the inbox.

Answer these 3 questions first, in under 5 minutes

Start with your customers. Do any of them buy on behalf of a company or an organisation? Someone who has to take your quotation to a manager for a signature, or a purchasing officer who has to attach documents to a system? If so, those customers already live in email every working day.

Next, open your LINE OA dashboard and look at the friend count, then compare it with how many customers actually bought from you last year. If the gap is wide, some people buy from you without ever adding your shop, and today you have no way to reach them again.

The last question: if you wanted to tell a longer story tomorrow, such as how to care for a product after purchase or a round-up of everything new this month, where would you send it? Few people read a page-long message in a chat to the end.

If the answer to all three is "no", your shop may not need to start email marketing yet. Use LINE OA to the full for now. If even one answer is "yes", the rest of this article should be worth your time.

LINE OA really is faster, and I won't argue with that

On speed alone, email can't compete with LINE. Thai customers have LINE open all day, and a message from your shop pops up alongside chats from friends and family. Many people check email once a day, and some don't even have an email app on their phone.

LINE OA also lets you talk back and forth instantly. A customer asks for a price, your admin answers, and the sale closes in one chat. For restaurants, clothing shops and beauty clinics, where most customers are individuals who decide quickly, LINE OA as the main channel is the right call. I'm not asking you to move anyone off LINE.

What I'd like you to consider is that email does a different job. It suits things that don't need to be fast but do need to last.

Where email marketing still wins for a business whose customers are on LINE

Business customers who decide as a group

Picture a factory that orders packaging boxes from you. The person messaging you on LINE may be a purchasing officer, the person who approves is a manager, and the person who pays is in accounting. One set of documents has to cross three desks. An email can be forwarded whole, attachments and all, with a date and a sender on it, and it can be found again by searching the company name. That is why B2B customers often ask for your email address in the very first conversation.

Quotations, receipts and documents customers need to keep

A LINE chat keeps scrolling up every day. To find a quotation sent three months ago, a customer has to scroll for a long time. In an inbox, they type your shop's name into the search box and it's there. Every time you send a document like this, your shop's name lands in the customer's inbox for a good reason, and it's the best moment to ask whether they'd also like your newsletter. Ask first, please. Don't add them yourself.

Customers who never added your LINE OA

Some customers don't add shops because they don't want a cluttered chat list. Some added you once and blocked you after too many messages. Some are foreign customers who may not use LINE at all. These people still buy from you, and many are happy to leave an email address if you tell them clearly what you'll send and how often.

Longer content customers want to read later

An after-installation care guide, a full term's class timetable, a seasonal menu round-up. Content like this is far easier to read in an email, with headings, images in order and links back to the detailed pages on your website. Customers can open it on a quiet Sunday evening without other chats popping up in between.

A list that belongs to your business

LINE OA charges for broadcasts through a monthly message quota, and going over it costs extra per message. I covered the plans in detail in our article on LINE OA package pricing for 2026, with a message quota calculator. More important than the cost, though, is that your LINE OA friend list lives inside LINE's system. You can only reach those people through LINE.

An email list that customers gave you with consent can be exported as a file, moved to a different email tool, and kept in use even if customers one day shift to another chat app. Email tools have their own fees and limits too, so open the official pricing page of any tool you're considering on the day you decide. The real difference is that this list travels with your business wherever it goes.

Collect emails from your website, the way customers are glad to give them

The best place to collect email addresses is your own website, because anyone who reaches it is already interested in your business. In my experience only a few spots really work: a newsletter sign-up at the end of an article, a tick box on your quotation request form, and the thank-you page after an order.

The key in every spot is saying plainly what you'll send, for example "a round-up of new products and promotions, once a month", and letting the customer tick the box themselves. A box you've pre-ticked, or quietly copying addresses from quotations into your newsletter list, leaves people wondering why they're getting your email, and that makes the spam button very easy to press. Spam complaint rate is a number Gmail and Yahoo use to judge senders directly, which I'll explain in the next section.

For the legal side of asking consent to collect personal data, I've explained it in our article on PDPA and whether your website form collects consent correctly. Please read it alongside this one before you open a sign-up form.

Before your first send, ask your web person about SPF, DKIM and DMARC

Since 1 February 2024, Google has applied its requirements for senders to Gmail accounts. All senders must set up SPF or DKIM for their sending domain and keep the spam rate reported in Postmaster Tools below 0.3%. Anyone sending more than 5,000 messages a day to Gmail accounts must set up both SPF and DKIM plus DMARC, and marketing messages must support one-click unsubscribe with a clearly visible unsubscribe link in the message body. I checked that page on 1 October 2026.

Yahoo published its own sender requirements, also enforced from February 2024, along the same lines. All senders need SPF or DKIM at a minimum and a spam rate below 0.3%. Bulk senders need both SPF and DKIM, a DMARC policy of at least p=none that passes, and one-click unsubscribe.

Most small shops never send 5,000 emails a day. So why care?

Because these three work rather like an ID card for your email. SPF says which servers are allowed to send email on behalf of your domain. DKIM is a digital signature that helps confirm the email really came from that domain and wasn't altered on the way. DMARC tells the receiver what to do with email that claims to be from your domain but fails those checks. Setting up all three while you're still sending small volumes is my own recommendation. Google's rule for ordinary senders asks only for SPF or DKIM, but setting everything up at the start is much easier than fixing it once your list has grown.

You don't have to do this yourself. All three are records in your domain's DNS, and your web person or IT team can set them up. You only need to ask them: does our domain have SPF yet, has the email tool we're going to use been set up with DKIM on our domain, and do we have a DMARC record? If they say everything is in place, ask them to send a test email to your Gmail, open it with Show original to look at the headers together, and have them point out whether each check passed.

"Our customers don't read email"

I hear this a lot, and I believe it's true for many customers. Someone with a single phone often has just the email account they created when setting it up, and opens it a few times a year. If nearly all your customers are like that, email marketing isn't worth the effort for your shop.

What I suggest is letting customers answer the question for themselves instead of us guessing for them. Open a sign-up box on your website, then send one email a month only to people who signed up. Try it for three months. If there's total silence, no clicks and no replies, you can stop having spent very little time. If people reply asking about products, there's a group of customers who really are listening through the letterbox, and they are often your most attentive readers.

Start early and the list builds early

An email list is something you can't go back in time to collect. Every day your website has visitors but no sign-up box, interested people leave without leaving a way to reach them. A sign-up box opened today means a full year of addresses a year from now. One opened next year starts from zero.

Writing skill builds the same way. The first issue is always the hardest: what to say, which picture to use. By the sixth, you'll know which topics customers click, which ones they reply to, and the newsletter starts writing itself from the questions customers asked that month.

The smallest newsletter you can really keep sending every month

It doesn't need to look like a big brand's. Four parts are enough. Begin with the one story you want to tell this month: a new product, a job you've just delivered for a customer, or the question customers asked most this month. Keep it to three or four short paragraphs with one image. Under it, place one or two links to pages on your website, so interested readers can read more or request a quotation.

Then add a line inviting conversation, such as "Just reply to this email if you have any questions." One reply is worth more than several numbers in a report. Finish with a footer carrying your shop's name, address, contact details and an easy-to-find unsubscribe link. Customers who can't find the unsubscribe button tend to press the spam button instead.

As for frequency, there's no single best number that fits every shop. Once a month is the rhythm I recommend to start with, because you can keep it up without hiring anyone. Once you're consistent, adjust based on how customers respond.

Real tool names you'll hear

Widely used email tools include Mailchimp, Brevo and MailerLite. All of them come with list management, sign-up forms, unsubscribe links and built-in reports. I won't quote prices or free plans here, because the terms change often. Checking the official pricing page on the day you sign up is the most accurate way.

When you talk to your web person, you'll also hear about Google Postmaster Tools, the Google tool that Gmail's sender requirements refer to for spam rates. And if many of your customers use iPhones, you'll hear about Mail Privacy Protection, which affects measurement. I explain it in the measurement section below.

What actually happened on our own website

After TumWebSME's website was rebuilt in 2026, we learned a lesson we still remember. The Google Ads conversion tag went live with the site and everything looked fine, but on the live site the tag wasn't actually running for about a week after the ads launched, because it sat in the wrong place. Clicks came in as usual, while conversions read zero.

What we took from it is simple: don't trust the settings page, check the real thing. The same applies to email. Before every real send, send a test to your own Gmail, click every link to make sure it goes to the right page, and try the unsubscribe link to see it really works. For your first issue, have your web person open Show original with you and look at the SPF, DKIM and DMARC results once more.

One more thing. Our sales team logs every call and every LINE chat with "where did you find us, and what did you search for?", because analytics tools can't see conversations inside LINE. Email is the same. A customer reads your newsletter and picks up the phone to call you, and no report will ever know unless your team asks.

A 5-step plan you can start this month

1. Ask your web person whether your domain has SPF, DKIM and DMARC in place.

2. Choose one email tool, check its price on the official page, and set up DKIM with your shop's domain.

3. Add a sign-up box to your website that says clearly what you'll send and how many times a month, and let customers tick it themselves.

4. Write your first issue using the four-part structure, send a test to your own inbox, and check the links and the unsubscribe button.

5. Send it for real, then book a time with yourself to review the results 7 days later.

How to measure when open rates are less reliable

Every email tool shows a big open rate figure in its report. That number is counted from remote content embedded in the email: when the recipient's device loads it, the system counts the email as opened. The catch is that Apple's Mail Privacy Protection in the Mail app, when turned on, privately downloads remote content in the background when a message arrives, instead of when it's viewed, and hides the recipient's IP address from senders. So people who use the Mail app with this feature on may be counted as "opened" without ever touching your email.

So I treat open rate as a rough signal only and give more weight to numbers that need someone to actually do something. The first is clicks. Add UTM tags to every link in your newsletter as explained in our article on UTM parameters and which channel brings customers, and Google Analytics will show which pages people visit after arriving from your email. The second is replies, which are easy to count by hand in the early months.

The third is unsubscribes per issue. If they jump after a particular issue, that content didn't match what customers expected when they signed up. Finally, have your sales team add "newsletter" as an answer in the "where did you find us" log, so you can see who called or messaged because of an email.

Back to the letterbox by the gate

The wooden letterbox at my family's house never competed with the telephone. Anything that couldn't wait came by phone, and anything worth keeping came through the letterbox. One house used both, and nobody ever asked which was better.

LINE OA and email marketing can live together the same way. Let LINE OA keep doing the fast conversations and closing sales, and put a small letterbox on your website where customers who want to read can drop in their own names. Start with one issue a month and see who writes back.

If you're about to build a new website and want a place to collect your own customer list on it from day one, take a look at what TumWebSME's website packages hand over to you, then tell us a little about your business. We'd be glad to talk it through.

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