The blast itself takes two minutes. Everything that decides whether it works happens before you press send. Here is the order to do it in.
Most failed blasts fail here, silently. Three things to do:
60XXXXXXXXX. Exports from POS systems and spreadsheets arrive as
012-345 6789, +60123456789, or with a leading apostrophe Excel added.
A good platform normalises these for you and tells you how many it could not parse.Write the message first, then look at the segment count — not the character count. The thing that catches people is that a single non-English character re-prices the whole blast: one emoji or one Chinese word drops your per-segment budget from 160 characters to 70. On a 5,000-recipient list that is the difference between 5,000 and 15,000 billed segments.
Two habits worth keeping: paste your draft into a segment calculator before you commit, and retype apostrophes and dashes rather than pasting them from Word — the curly versions are Unicode.
Malaysian operators penalise messages containing protected international brand names at RM1.50 per segment. Mentioning a major marketplace, courier or payment brand in your promo can cost several times the value of the blast. If your platform does not warn you before charging, you will only find out when the penalty appears weeks later.
Always. On a real handset, on the network most of your customers use. You are checking four things a preview cannot show you: what the sender appears as, whether the line breaks survived, whether your short link is clickable, and how long it took to arrive.
There is no magic hour, but there are bad ones. Avoid before 9am and after 9pm — late marketing SMS generates complaints, and complaints are what get a sender filtered. For time-sensitive promotions, sending a few hours before the offer window beats sending at the moment it opens.
After the blast, the numbers that matter are not "sent". They are these:
| Status | Meaning | Charged? |
|---|---|---|
| Delivered | The network confirmed it reached the handset | Yes |
| Undelivered | Accepted by the operator but never reached the handset — phone off, number recycled, filtered | Yes |
| Rejected | Never submitted at all — invalid number, blocked content | No, refunded |
Undelivered and rejected are not the same thing and should never be merged into one "failed" number. Operators bill on submission, so a message accepted and then not delivered is still charged; a rejected one is not. A provider that shows you a single "failed" count is making their invoice impossible to reconcile.
A rising undelivered rate on one network usually means content filtering, not broken phones — that is the point to read why SMS is not delivered.
Manual blasts are fine monthly. If you are pasting the same list every week, or triggering messages off events in your own system, move to the API — your CRM sends directly, and delivery status comes back per number.
They describe the same delivery mechanism. "Blast" usually implies a one-off campaign sent manually to a list you uploaded; "bulk SMS" is the general category, including automated and transactional sending. Same networks, same per-segment billing.
On HantarSMS, up to 5,000 recipients per submission, and you can queue as many submissions as your credit covers. Larger lists are better split anyway — it lets you check delivery on the first batch before committing the rest.
SMS has no spam folder, but Malaysian operators do filter. What triggers it: protected brand names, URL shorteners on shared domains, high complaint rates, and sending to lists that never opted in. A blast to a consented list with your own sender identity rarely has delivery problems.
You are charged for messages successfully submitted to the operator, because that is when the operator charges us. Numbers we could not submit at all — invalid format, blocked content — are refunded automatically. That is why the report separates "rejected" from "undelivered".
Business hours, avoiding before 9am and after 9pm. Beyond that, timing relative to the offer matters more than the clock: a few hours of lead time before a promotion opens consistently outperforms sending at the moment it starts.
Send to your own number first, check the delivery report, then decide.