SMS & MMS articles

One festival window per month, each with send timing, image subject, copy skeleton (unsubscribe line included) and call-to-action type. MMS templates that retail, F&B, beauty and education businesses can copy and edit, all within the 800×800 and 230KB spec and carrying the unsubscribe and sender details the Unsolicited Electronic Messages Ordinance requires.

What size should an MMS image be? How big can the file be? Can you send a GIF? One article on the carriers' 230KB total payload, the 800×800 pixel limit, how iPhone and Android render differently, Canva and Photoshop export steps, and a pre-upload checklist.

MMS travels over a data connection and bills per message, so it fails in ways SMS never does. How MMS charging actually works, six reasons a message never arrives, and the two ways a business can send it — dashboard or API — with the real spec limits.

What is SMS: 短訊 (Hong Kong) and 簡訊 (Taiwan) are the same service. 160 / 70 character billing, OTP use cases, # Sender ID and Taiwan white-listing. Businesses: SMS API docs and apply for a +886 test key.

"Submitted" is not "delivered". A breakdown of the two-tier SMS reporting model, what every status code means, and how UNDELIV, EXPIRED and REJECTD should each be handled.

What a grey route is, how to spot one, and what it actually costs you in deliverability, sender name integrity, DLR honesty and regulatory exposure. With four tests you can run yourself.

Why does SMS fail to arrive even when the API returned success? The real causes are more numerous than you would expect — from carrier filtering and SIM status to grey-route forwarding.

What is MMS: picture-and-text to a mobile number, billed per message (~230KB), not per SMS segment. How it differs from SMS and why images fail. Hong Kong promotions on the MMS page; Taiwan on mms-tw.

How SMS and MMS reach Hong Kong users roaming abroad — delivery, delay, and how charging works.

Sending SMS or MMS has become the most effective and direct way for major businesses and brands to communicate with customers.

Location-based SMS fires by geography, not by blasting a city-wide list. How it works in Hong Kong, what UEMO requires, and when business SMS or MMS is the better channel.

Once a message exceeds two SMS segments, MMS becomes the cheaper option — each MMS carries up to 230KB and can embed an image to lift engagement.

SMS has been on the market for years and businesses still depend on it as the most direct and immediate way to reach customers, because no other form of communication matches its immediacy.

Have you ever registered for a service online, been told an SMS would arrive to complete the process, waited and waited, and never received anything — so the registration never completed?

Using international SMS to communicate with customers around the world — the five things to check when choosing a provider, and why direct routes matter.