How antispam works on Xiaomi Redmi Note: a full analysis of the mechanisms of protection

Xiaomi Redmi Note smartphones have long proven to be reliable devices with advanced security features. One of the key features that users often underestimate is the built-in anti-spam system. It works on several levels, from filtering to filtering. SMS And calls to block suspicious notifications and phishing protection, but how exactly does this system determine what is spam and what is not? And why do legitimate messages sometimes get blacklisted»?

In this article, we will analyze in detail how antispam works on Redmi Note, what algorithms it uses. MIUI To filter out unwanted content, and what to do if the system mistakenly blocks important notifications, we will pay special attention to the settings that are available to the user, from the basic parameters in the Security menu to hidden functions activated via ##4636## or ADB. We also debunk the myths that antispam “eats the battery” or “brakes the phone” – in fact, its impact on performance is minimal if you properly set scanning priorities.

If you have ever wondered why some of them SMS They arrive with a delay or why calls from unknown numbers are automatically reset – you will find the answers below. And for those who want to protect their Redmi Note from fraud, we have prepared step-by-step instructions for fine-tuning anti-spam, including working with whitelists / blacklists and integrating with Xiaomi cloud databases.

Anti-spam architecture in MIUI: How it works under the hood

The anti-spam system in MIUI (Xiaomi’s branded shell is built on three key components:

• 📱 Local filter – analyzes incoming SMS, Calls and notifications directly on the device, comparing them to spam patterns stored in the smartphone’s memory.
• ☁️ Cloud database – synchronized with Xiaomi servers, where spam numbers and phishing links from around the world are collected.
• 🤖 Machine learning – algorithms analyze user behavior (such as what messages they ignore or flag as spam) and adapt filters to their habits.

Interesting fact: the anti-spam in Redmi Note works even without an Internet connection, but its effectiveness in this case is reduced by 30-40%. MIUI 14), whereas the cloud base has more than 2 million records, and the cloud anti-spam does not transmit your contents. SMS to Xiaomi servers – only metadata is analyzed (sender number, message type, links availability).

It's important to understand that antispam is not only integrated into Messages or Phone applications, but also into system services, such as blocking:

• 📧 Suspicious notifications from apps (such as those with the suggestion to “win an iPhone»).
• 🔗 Phishing links in the Mi Browser browser or messengers.
• 📞 Robophones with switched numbers (spoofing).

The system does not just remove spam, it categorizes it into categories: “Advertising”, “Fraud”, “Unsolicited Notifications”, which helps the user to navigate blocked content faster and, if necessary, recover mistakenly blocked messages.

Antispam settings: where to look and what to include

By default, anti-spam on Redmi Note is activated, but its effectiveness depends on the correct setting. → Annexes → Application management → Security is possible:

• 🔄 Turn on/off automatic filtration SMS (recommended to leave on).
• 📵 Set up a lock on unknown calls (useful for fighting robots).
• 🌐 Activate link verification in messages (phishing protection).
• 📊 View statistics of blocked messages and calls.

However, the most flexible settings are hidden deeper, such as setting up a whitelist (numbers that will never be blocked) to:

1. Go to Settings → Memory and applications → Security → Antispam.
2. Select the tab "White list".
3. Add numbers manually or import from contacts.

For advanced users, settings through ADB. For example, the command below disables cloud-based spam verification (not recommended, but may be useful for testing):

adb shell settings put global spam_protection_cloud_enabled 0

Activate automatic filtration SMS|Add important numbers to the whitelist|Activate verification of links in messages|Update your cloud database manually (once a week)|Disable notifications from blocked numbers-->

You should also pay attention to the settings of the Messages app. Here you can:

• 🔍 Enable search for spam messages (useful if you need to find blocked) SMS).
• 🗑️ Set up auto-clean spam (e.g. delete messages older than 30 days).
• 🛡️ Activate SMS fraud protection (blocks messages requesting money transfer).

Cloud Antispam: How Xiaomi Collects Data and Why It’s Safe

Many users fear that Xiaomi’s cloud-based anti-spam is transferring personal information to the company’s servers, and the mechanism is as follows:

1. Local analysis: when it comes SMS or a call, the system first checks it on a local database.
2. Anonymized query: If a message is suspicious, only the sender’s hash number and content type (e.g., “contains a link”) are sent to the server. SMS nontransmittable.
3. The answer from the server: the cloud returns a verdict – “spam” or “non-spam” as well as a category (advertising, fraud, etc.).

For additional protection, Xiaomi uses:

• 🔐 Traffic encryption (all requests to the cloud are transmitted via protocol) HTTPS).
• 🌍 Regional servers – data of users from Russia are processed on servers located in the Russian Federation, which reduces the risk of leakage.
• 🗂️ Automatic deletion of logs – information about blocked messages is stored for no more than 7 days.

If you don’t trust cloud antispam, you can turn it off in your settings, but it will reduce filtering efficiency by 40-50%.The alternative is to use third-party antispam apps like Truecaller or Kaspersky Who Calls, but they also require access to your contacts and call histories.

Black and White Lists: How to Manage Locks Manually

Automatic anti-spam is not perfect, sometimes it skips spam or it blocks legitimate messages, and blacklists and whitelists help.

The blacklist allows you to manually add numbers that you want to block, and you can do this in a number of ways:

• 📞 Through the call log: swipe left by number → «Lock down».
• 💬 In the app “Messages”: a long press on SMS → «Block the sender».
• ⚙️ In anti-spam settings: Settings → Security → Antispam → Blacklist.

The whitelist, by contrast, ensures that messages and calls from selected contacts are never blocked.

• 🏦 Bank notifications (SMS from Sberbank, Tinkoff, etc.).
• 🚑 Emergency services (112, ambulance, MOE).
• 👨‍💼 Important business contacts.

Important: if the number is added to both lists (black and white), whitelist priority is given, and it is worth remembering that some system numbers (for example, from a carrier) are by default whitelisted and cannot be blocked.

💡

If you often receive spam from numbers masquerading as bank numbers (for example, +7 9xx-xxx-xx-xx "Sberbank," add the Sberbank template to the blacklist (with quotation marks) and block all messages that have this word in the sender's name.

Common Problems and Their Solutions

Despite the advanced algorithms, the anti-spam on Redmi Note sometimes doesn’t work properly, and here are the most common problems and ways to fix them:

1.Legitimate SMS spamming

Reason: The sender number is not on the whitelist, or the message contains “suspicious” words (e.g., “transfer”, “payment”).

Decision:

• Add the number to the whitelist.
• Check the text of the message for the presence of stop words (the list can be viewed in Settings). → Security → Antispam → Filter settings).

2.Spam calls go through the filter

The reason: the number is not entered in the cloud database Xiaomi, or rings a robot with a changed number (spoofing).

Decision:

• Enable the option to “Block Unknown Numbers” in your phone settings.
• Install a third-party application to block spam (such as Truecaller).

3 Antispam 'eats' the battery

Reason: Constant cloud sync or too aggressive scanning is enabled.

Decision:

• Turn off background synchronization in Settings → Accounts. → Mi Account → Synchronization.
• Set the cloud base update interval to “1 times a day” instead of “automatically”.

💡

If anti-spam blocks important notifications (such as confirmation codes), check if the sender number has been blacklisted by mistake. Also make sure that the Messages app settings have disabled the option to “Filter Service” SMS».

4.After the update MIUI Antispam has stopped working.

Reason: Reset security settings or conflict with new system applications.

Decision:

• Reboot the phone.
• Update the Security app through the Mi App Store.
• Reset your anti-spam settings to factory (Settings) → Annexes → Application management → Security → Reset).

⚠️ Note: If you use custom firmware (like LineageOS or Pixel Experience), built-in anti-spam MIUI It won't work, and then you'll have to install third-party solutions like Call Blocker or something like that. SMS Filter.

Hidden functions of anti-spam: what can MIUI, but not public

In addition to the standard settings, the MIUI There are a few hidden anti-spam features that few people know about:

1. Geolocation locking

Antispam can block calls and SMS For example, if you never talk to a number from Nigeria or India, you can block it completely:

1. Activate the Developer Mode (as described above).
2. Go to Settings → Additional → For developers.
3. Find the international call filter option and add country codes (e.g, +234 for Nigeria).

2. Keyword Filtering

You can set up a lock on messages that contain specific words or phrases, for example, if you get a lot of spam with suggestions to “make money,” add this phrase to the stop list:

• Go to Settings. → Security → Antispam → Filter settings.
• Select “Keywords to lock.”
• Add comma phrases (registration is not important).

3. Log of blocked messages

All blocked. SMS The calls are stored in a hidden log that can be exported for analysis:

1. Open the Security app.
2. Go to the Antispam section.
3. Slap the icon «⋮» (three dots) in the upper right corner and select "Export log».

The log is saved in.csv format and can be useful if you want to complain to the operator about spammers.

4.Integration with Google Messages

If you use Google Messages instead of the standard Messages app, anti-spam MIUI It's still going to work, but it's going to work with limitations, to improve filtering:

• Enable the option “Spam Protection” in Google Messages (Settings) → Protection against spam).
• Allow the Security app to access SMS permission settings.

⚠️ Note: Hidden anti-spam features may vary depending on the version MIUI Redmi Note models, on some devices (e.g. Redmi Note 12 Pro)+) Additional options are available, such as blocking regular expressions or integration with Mi AI voice-calling.

FAQ: Frequent questions about anti-spam on Xiaomi Redmi Note