How to grow your email list — sign-up forms, welcome emails and re-engaging inactive subscribers

Key takeaways

• A list is only worth as much as people’s wish to hear from you; bought or scraped lists bring complaints and bounces, not business.
• Hong Kong’s Personal Data (Privacy) Ordinance requires consent before personal data is used for direct marketing, with notice of the data and the classes of products or services involved; Taiwan’s PDPA requires marketing to stop once the person refuses; UK law generally requires specific consent for marketing email.
• Place sign-up forms where interest is highest — your website, the end of articles, checkout, events — and avoid pop-ups that cover the whole mobile screen.
• Send a welcome email immediately, saying what subscribers will receive and how often.
• Deal with long-term non-engagers regularly: try to re-engage them, and stop mailing those who stay silent to protect your sender reputation.

A bigger list is not the goal — a list of people who want your email is. A list built from genuine sign-ups beats a large, indifferent one on opens, clicks and conversions, and it does not drag down your sender reputation. This guide covers growing a list lawfully and effectively, welcoming new subscribers, and handling the ones who have gone quiet.

Principle first: mail only people who want it

Bought, swapped or scraped addresses belong to people who do not know you and never agreed to hear from you. Mailing them typically brings a wave of bounces and “Report spam” clicks that lowers your whole sending domain’s reputation — and hurts delivery to your real customers too. See How to keep your email and newsletters out of the spam folder — a complete guide for business senders.

On the legal side, when collecting subscribers:

• Hong Kong: under the Personal Data (Privacy) Ordinance, a data user must obtain the data subject’s consent before using personal data for direct marketing, and tell them the kinds of personal data to be used, the classes of products or services to be marketed, and their right to opt out (PCPD: The Ordinance at a Glance).
• Taiwan: Article 20 of the Personal Data Protection Act requires marketing to stop once the person refuses, and a way to refuse to be offered the first time you market to them (Laws & Regulations Database).
• United Kingdom: marketing email to individuals generally needs their specific consent, with a narrow “soft opt-in” for existing customers (ICO guidance).
• Elsewhere: rules vary, so check what applies where your recipients are.

This is a summary, not legal advice.

Where to put sign-up forms

Put forms where people are already interested in what you offer:

• Your website: the footer, the end of blog posts, the side of product pages. Finishing a useful article is a natural moment to subscribe.
• Checkout or registration: add a newsletter option that people tick themselves, not one that is pre-ticked.
• Events and trade shows: let attendees sign up on a tablet or via a QR code, and tell them what they will receive.
• Social media: put a sign-up link in your profiles and posts to bring followers onto email.
• Your existing emails: add a “forward to a friend” or subscribe link so readers can pass your content on.

Keep forms short. Ask for an email address, and perhaps a first name; gather more later, through the welcome email or a preference page.

Use pop-ups with care. Google notes that dialogs covering the whole page make it hard for search engines to understand your content and may hurt search performance, and recommends banners that take up only a small part of the screen instead (Google Search Central: Avoid intrusive interstitials). On mobile especially, avoid full-screen overlays.

Give people a reason to subscribe

Most people will not hand over an email address for nothing. Say clearly what they get, and offer an incentive related to your business:

• Practical resources: guides, checklists, templates, reports;
• Member offers: a new-subscriber discount, members-only events;
• Learning: webinars, introductory courses, one-to-one consultations.

Keep the incentive relevant to what you will send afterwards. People who subscribe just to enter a prize draw may have little interest in your newsletter, and are quick to unsubscribe or complain.

Double opt-in and the welcome email

Double opt-in: after signing up, the subscriber receives a confirmation email and joins the list only after clicking the link. It weeds out mistyped addresses and sign-ups made with someone else’s address, so the list is cleaner; the cost is that some people never confirm. For brands that care about list quality, it is usually worth it.

The welcome email: send it straight away — this is when the subscriber is most interested in you. It should:

• thank them and deliver the promised incentive (a download link or a discount code);
• say what they will receive and roughly how often;
• introduce who you are and what to read first;
• ask them to add your sending address to their contacts.

You can also extend it into a welcome series over the first days or weeks: introduce the brand, share useful content, and only then make an offer. For matching content to where each subscriber is, see Email marketing strategy — using the funnel to turn strangers into loyal customers.

Let people choose, not just leave

Offer a preference page where subscribers can pick:

• the topics they want (only new products, or only events);
• how often they hear from you (weekly or monthly);
• the language they prefer.

Many people unsubscribe not because they dislike you, but because there is too much email or it is not relevant. Letting them adjust, rather than leave entirely, keeps more subscribers.

Handling inactive subscribers

Subscribers who have not engaged for a long time contribute nothing and pull down your overall engagement, which affects sender reputation.

What counts as “inactive”? It depends on how often you send and your business cycle: for a weekly newsletter, a few months without engagement is a long time; for something people buy once a year, allow longer. Note that some recipients’ opens cannot be recorded at all (see How to improve email open rates — and what to measure now that opens are unreliable), so look at clicks and purchases over a longer period too.

A re-engagement sequence might run:

1. Ask first: “Do you still want to hear from us? What would you like?”, with a link to the preference page.
2. Give a reason to come back: a member offer, your most popular recent content, or what has changed.
3. A final message: say plainly that you will stop emailing if you do not hear back, and give them the option to stay.

A common, effective shape for that final message: a subject line that simply asks “Is this goodbye?”, a gentle note that you have noticed they have not opened your emails lately, and a few clear choices — “Keep me subscribed”, “Update my preferences”, “See what’s new”.

Stop mailing those who still do not respond. The list gets smaller, but everyone left is genuinely interested, and both sender reputation and results improve.

FAQ

Can I add business cards collected at an event to my newsletter list?
It depends on whether you explained the purpose and obtained consent when collecting them, and on the law where the recipient is — Hong Kong’s privacy ordinance, for example, has consent requirements for direct marketing. The safest route is to send a single invitation to subscribe and let them choose.

Should I use double opt-in?
If list quality matters to you, or you have had fake sign-ups, yes. Some people will not confirm, but the list you keep is more reliable.

How often should I clean my list?
Remove hard-bounced addresses immediately. Review inactive subscribers periodically — quarterly, for example — try to re-engage them, then decide whether to stop mailing.

Can I email someone who has unsubscribed?
No. Add unsubscribed recipients to a suppression list so that no department and no campaign sends them marketing email again, unless they later choose to subscribe again.

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UFOSEND’s EDM email marketing service organises subscribers into lists by source, product or sign-up form, layers tags to build precise segments, and automatically adds bounces, complaints and unsubscribes to a suppression list shared across all your campaigns.