Protect a Telegram group from spam without breaking the conversation
Build an anti-spam policy around entry, useful messages and recovery. Choose Telegram and Defendy controls, test edge cases and roll changes out safely.
Imagine a software community opening its Telegram group to the public. People arrive with useful bug reports, documentation links and screenshots. So do accounts advertising unrelated services. An administrator blocks every link. The advertisements disappear, but now members cannot share the issue tracker that makes support possible.
That is a hypothetical example of a policy problem disguised as a settings problem. A useful anti-spam setup has to preserve the work the group exists to do. Start by deciding who can enter, what messages belong and who will correct a mistake. Then choose controls for those decisions.
This guide helps you design that baseline. For the sequence of screens and checks, use the step-by-step Defendy setup.
Describe the abuse before choosing a filter
Collect a small set of recent unwanted messages and a separate set of valuable messages that look similar. Remove private information you do not need for the exercise. Label the problem in each example as specifically as possible.
An unsolicited promotion, an off-topic question and a heated disagreement need different responses. A URL is a format, not a judgment about its value. Repeated questions may mean your instructions are hard to find. An unfamiliar name or a profile without a photo is not enough evidence to treat a member as an abuser.
Look at where the unwanted behavior begins:
- At entry: newly joined accounts immediately post advertisements. Review the join route and whether a challenge would help.
- In messages: members post prohibited destinations, promotional text or unwanted forwards. Match the rule to that content.
- In message volume: the conversation becomes unreadable because messages arrive too quickly. Consider a rate-limiting control.
- After intervention: a person repeats an understood violation or targets another member. A moderator needs to make a behavioral decision.
This separation also helps you avoid tuning the wrong control. Increasing text-filter strictness will not necessarily solve a burst of ordinary stickers, and making a CAPTCHA harder will not prevent someone who passed it from advertising later.
Give each layer a clear job
The following map describes responsibilities. It is not a diagram of Defendy's internal processing order.
| Decision | Where it belongs | Evidence that it works |
|---|---|---|
| Entry route and group-wide permissions | Telegram group settings | A regular member can join and send the content the group needs. |
| Newcomer verification | Defendy CAPTCHA | Success, failure and timeout each have an understood outcome. |
| Message policy | Text, link, forward and stop-word filters | A prohibited example triggers; a similar useful example survives. |
| Exceptions and appeals | Human moderators, supported by selected-event logs | Someone can explain a decision and correct access or warning points. |
Telegram's native slow mode controls the interval between messages. It can make a busy conversation easier to follow, but it does not classify an individual message as advertising. Telegram's slow-mode explanation.
Another important distinction is link previews. Removing permission to show a preview does not prohibit a URL in the text. Use a link-filter policy when you need to remove particular links. Telegram's permission definitions.
If the problem is comments beneath channel posts, check the linked discussion group. That is where the comment conversation lives. See Telegram's description of comments and the channel-comment protection guide.
Write a baseline that fits the community
For our hypothetical software-support group, the administrator might choose this starting policy:
- Members may share documentation, issue reports and relevant technical references.
- Unsolicited paid-service offers and invitations to unrelated communities are prohibited.
- A quotation of an abusive message for reporting purposes deserves review rather than an assumption that the reporter is the advertiser.
- Newcomers must have a practical way to complete any entry check and to ask for help if it fails.
- One moderator owns the initial configuration; another can review a disputed decision.
The distinction between external websites and Telegram destinations is useful here. In Anti-spam → Links, Defendy provides separate Websites and Channels and chats sections. Each offers Delete, Blacklist or Ignore. A group that relies on technical references might start by blocking known unwanted websites while applying a narrower policy to community invitations. Inspect exceptions instead of assuming that a familiar destination always passes. Link-filter settings.
An exception in one filter is not a promise that every other filter will allow the message. A permitted documentation link can still sit inside text that another enabled rule considers a violation. Record which rule acted before widening an exception.
Use Anti-spam → Text for text-spam checks and Stopwords for your own expressions. Avoid broad entries such as “free,” “job” or “support” merely because advertisements contain them. Those words may also be central to legitimate questions. Pick a distinctive phrase and test close alternatives. Stop-word matching explained.
CAPTCHA is an entry check, not a permanent certificate of good behavior. A longer or more complicated challenge also creates work for legitimate newcomers. Choose the supported join mode deliberately, then test the experience on the kind of device and connection your members use. CAPTCHA setup.
Understand what happens to the message and the member
A moderation rule can have two separate consequences: removal of the message and an action against its author. A gentle-sounding action does not make the entire rule non-destructive.
Defendy's text filter defaults to message deletion, and the current Text screen does not expose a deletion switch. Choosing None under punishment does not create an observation-only mode. Choosing Warn can still remove the message and add points that reach an existing punishment threshold. Text anti-spam settings, warning behavior.
Use a separate test group without valuable conversation while learning these outcomes. If you do not yet want member restrictions, choose no additional punishment and still account for deletion. Before enabling warnings, review the event's weight, the member's existing points, the thresholds and the durations. A preset's friendly name is not a substitute for reading its actions.
Treat AI verification as a later configuration decision. Defendy's automatic AI path is conditional on settings and service availability; it does not mean every message receives a conversation-aware review. A useful baseline should not depend on a promise of perfect classification or a guaranteed human-review queue. AI spam-check scope.
Build a test set around the work members actually do
A test made entirely of obvious advertisements can make a harmful policy look successful. Include content that the group cannot afford to lose. Here is a hypothetical set for the support community; these are desired policy outcomes, not claims about a completed classifier test.
- Normal question: “Does this release support the older file format?” Expected: remain visible, no sanction.
- Useful reference: a relevant documentation or issue-tracker link. Expected: pass under the chosen destination policy.
- Unrelated invitation: a harmless invitation to a test chat you control. Expected: removed if that kind of invitation is prohibited.
- Promotion without a link: an invented unsolicited offer, without a real seller's details. Expected: exercise the text-spam rule.
- Report containing a quotation: “Someone sent me ‘guaranteed profit, DM me’; should I report it?” Expected: allow a legitimate request for help or provide a workable moderator-review route.
- Two ordinary messages in quick succession: expected outcome depends on Telegram slow mode, not on the advertising policy.
Send the examples as a regular member who has no moderation role or exemption. Testing only from an administrator account may exercise a different path. For each case, record the saved setting, the expected result, the observed result and any log event.
If a useful message fails, identify the responsible rule. Tighten an overbroad phrase, revisit a destination exception or pause the filter while you investigate. Repeat the entire set after a change: an exception that fixes one report may also allow the unwanted message you started with.
Roll out during a period you can supervise
Start with one module in the test group. Once its behavior is understandable, reproduce those settings in the real group while a moderator is available. This is a deliberate group-by-group check; do not assume settings automatically propagate to every community you manage.
Check persistence as well as appearance. Ordinary switches save when changed, while separate forms may require Save. After a failed request, reopen the section and read the stored value. If the app reports that a write succeeded but refreshing failed, refresh the view before submitting the change again.
Connect logging for the event categories you need and verify that a harmless test event reaches the chosen destination. Logging does not supply a complete transcript of every message or guarantee that every possible action was recorded.
Review allowed conversation alongside removals. Ask whether members can still share references, whether newcomers are completing entry checks and whether people can contact a moderator after a mistake. A quiet group is not necessarily a healthy one, and an empty appeals inbox does not prove there were no false positives.
Move to another module only when you can explain the current rule, demonstrate a useful message passing and recover from an incorrect action. Otherwise additional filters will make the cause harder to isolate.
Have a recovery plan before you need it
If a rule starts removing useful posts, stop the repeated harm first: disable the responsible filter or restore its previous setting. Note the time and the rule involved. Check the member's access and warning points separately. Correcting points does not necessarily lift a restriction, and lifting a restriction does not undo a deleted message. Ask the author to repost only after the faulty rule has been addressed.
During a sudden influx, act on the source of the problem. An administrator can temporarily adjust Telegram posting permissions or slow mode, review the join route and handle offending accounts. Tell members what changed and when someone will reassess it. Temporary emergency restrictions need an owner who will remove them when they stop being useful.
Defendy's dedicated anti-flood module is still marked as planned. Do not build this plan around an available “N messages in N seconds” counter or automatic activation by traffic level. Use the controls that are actually available and check the feature statuses.
The end state should be easy to describe: a legitimate newcomer can join, a useful message can be posted, an unwanted message has a clear rule, and a mistake has a human route to correction. That is a baseline you can improve without making the group unusable.
Review note
Reviewed on October 5, 2026 against current Defendy settings and handlers and the linked Telegram primary sources. Scenarios are illustrative, not reports of live-group experiments. Verify feature availability and saved values in your own Mini App before rollout.
