Key Takeaways
- MMS on an Android SMS gateway is still your SIM talking to the operator’s MMS center. It is not a CDN.
- Attachments fail for APN, size, roaming, and recipient handset reasons that SMS does not have. Always keep a text fallback.
- Do not use MMS as the OTP channel. Codes belong in a short GSM-7 SMS.
- Resize images. A 12 MB site photo will not leave the radio. Aim well under typical carrier caps.
- Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Operator MMS tariffs are usually higher than SMS — budget airtime separately.
What MMS is on this path
Product surface: MMS gateway on your own SIM. The Android radio talks to the operator multimedia center. We do not host a public CDN of your floor plans. This overview is when that path is honest — and when a link in SMS is the real product. Hub: how an Android SMS gateway works.
If the job is “they must see the photo,” you still send the URL. MMS is a courtesy, not a contract.
When SMS wins instead
| Job | MMS? | Better default |
|---|---|---|
| Login OTP | Never | Short GSM-7 SMS |
| Tracking link | Rarely | SMS with HTTPS |
| Field photo to one tech | Maybe | MMS + URL twin |
| Open-house flyer to 4,000 leads | No | SMS + hosted image |
| PDF contract | Usually no | Portal; SMS nudge |
APN, size, and the SIM
MMS needs mobile data and a correct APN. Wi-Fi-only pairing will send SMS and fail pictures. Carrier caps are often a few hundred KB; some allow more. Roaming MMS is folklore until you measure it. GSMA messaging context: GSMA. Not a size-limit SLA we publish per operator.
Ship attachments without lying
- Confirm the feature path. Read the MMS product page. Do not invent a second protocol in your backend.
- Enable MMS APN on the gateway phone. Operator APN, mobile data on, not Wi-Fi-only. Test with the SIM that will send production.
- Resize before POST. JPEG under typical carrier limits. Strip EXIF GPS if the image is a field photo of a home or clinic.
- Always send a text twin. Caption + HTTPS URL. If MMS dies, the job still exists.
- Canary three recipient types. Same operator, other operator, iPhone. Watch DLR honesty — MMS receipts lie more than SMS.
- Keep MMS off the OTP device. Photo jobs queue and stall login codes. Separate deviceIds.
Setup: device setup. DLR honesty: delivery reports. Live fields: SMS API documentation. Transactional jobs that should stay text: transactional SMS.
Never put OTP in a picture
Accessibility, filtering, and SMS Retriever all assume a short text body. Isolate radios with multi-device and dual SIM. Dual SIM is not a second battery for a stuck MMSC.
Cost shape
Service pricing is based on device count and total SMS sent through the gateway. You need a working Android phone with a SIM and SMS credit from your mobile operator. Operator message costs are yours—we do not sell carrier SMS balance. Operator MMS is often billed higher than SMS. Free is 300 SMS lifetime for canaries, not a photo catalog. Paid from $19/month. Device and SMS volume pricing.
Next steps
APN on, images small, URL always, photos off the OTP SIM. Then read the feature page for the product surface — not as a promise that every JPEG arrives.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- MMS gateway on your own SIMMultimedia where supported
- SMS API documentationLive endpoint reference
- device and SMS volume pricingPlans and allowances
- Android SMS gateway product guideDefinition, product, and how to buy
