Fully featured, open source, privacy friendly email app for Android
This report presents the forensic synthetic code analysis of M66B/FairEmail, a Java project with 4,487 GitHub stars. SynthScan v2.0 examined 853,070 lines of code across 2301 source files, recording 330 pattern matches distributed across 7 syntactic categories. The overall adjusted score of 2.7 places this repository in the Likely human-written band.
The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).
Longitudinal tracking requires multiple scan runs. Once this repository is re-scanned after new commits land, this chart will visualise how the synthetic code signal evolves over time — enabling you to detect whether AI authorship is growing, stabilising, or being actively corrected by human engineers.
Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.
This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.
The scanner identified 330 distinct pattern matches across 7 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.
Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| CRITICAL⚡ | index.html | 184 | at io.requery.android.database.sqlite.SQLiteConnection.nativeExecute(SourceFile:-2) | CODE |
| CRITICAL⚡ | index.html | 185 | at io.requery.android.database.sqlite.SQLiteConnection.execute(SQLiteConnection:595) | CODE |
| CRITICAL⚡ | index.html | 186 | at io.requery.android.database.sqlite.SQLiteSession.endTransactionUnchecked(SQLiteSession:447) | CODE |
| CRITICAL⚡ | index.html | 187 | at io.requery.android.database.sqlite.SQLiteSession.endTransaction(SQLiteSession:411) | CODE |
| CRITICAL⚡ | index.html | 188 | at io.requery.android.database.sqlite.SQLiteDatabase.endTransaction(SQLiteDatabase:551) | CODE |
| CRITICAL⚡ | FAQ.md | 191 | at io.requery.android.database.sqlite.SQLiteConnection.nativeExecute(SourceFile:-2) | CODE |
| CRITICAL⚡ | FAQ.md | 192 | at io.requery.android.database.sqlite.SQLiteConnection.execute(SQLiteConnection:595) | CODE |
| CRITICAL⚡ | FAQ.md | 193 | at io.requery.android.database.sqlite.SQLiteSession.endTransactionUnchecked(SQLiteSession:447) | CODE |
| CRITICAL⚡ | FAQ.md | 194 | at io.requery.android.database.sqlite.SQLiteSession.endTransaction(SQLiteSession:411) | CODE |
| CRITICAL⚡ | FAQ.md | 195 | at io.requery.android.database.sqlite.SQLiteDatabase.endTransaction(SQLiteDatabase:551) | CODE |
| CRITICAL | app/src/main/java/androidx/room/TableInfo.java | 694 | ? Collections.nCopies(columns.size(), androidx.room.Index.Order.ASC.name()) | CODE |
| CRITICAL | …java/androidx/emoji2/text/flatbuffer/MetadataList.java | 34 | public androidx.emoji2.text.flatbuffer.MetadataItem.Vector listVector() { return listVector(new androidx.emoji2.text.f | CODE |
| CRITICAL | app/src/main/java/javax/mail/EventQueue.java | 165 | at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireInterruptibly(AbstractQueuedSynchronizer.java:1248) | CODE |
| CRITICAL | app/src/main/java/javax/mail/EventQueue.java | 166 | at java.util.concurrent.locks.ReentrantLock.lockInterruptibly(ReentrantLock.java:344) | CODE |
| CRITICAL | app/src/main/java/javax/mail/internet/MimeUtility.java | 1340 | javax.mail.internet.MimeUtility.class.getResourceAsStream( | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/MessageHelper.java | 4945 | if (!org.apache.poi.hsmf.datatypes.MAPIProperty.RTF_COMPRESSED.equals(attr.getProperty()) && | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/MessageHelper.java | 4946 | !org.apache.poi.hsmf.datatypes.MAPIProperty.BODY_HTML.equals(attr.getProperty())) | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/MessageHelper.java | 5305 | at com.sun.mail.util.ASCIIUtility.getBytes(ASCIIUtility:279) | CODE |
| CRITICAL | …p/src/main/java/eu/faircode/email/EditTextCompose.java | 814 | // at com.android.internal.inputmethod.EditableInputConnection.commitText(EditableInputConnection | COMMENT |
| CRITICAL | …/src/main/java/eu/faircode/email/EncryptionHelper.java | 34 | at org.apache.harmony.security.utils.JarUtils.verifySignature(JarUtils.java:223) | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/FragmentOAuth.java | 425 | at net.openid.appauth.browser.CustomTabManager.bind(SourceFile:27) | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/EditTextPlain.java | 88 | at com.android.internal.widget.EditableInputConnection.commitText(EditableInputConnection.ja | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/EditTextPlain.java | 91 | at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper. | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/EditTextPlain.java | 113 | at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper.ja | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/ActivityMain.java | 377 | java.lang.NullPointerException: Attempt to invoke virtual method 'int com.android.se | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/ActivityMain.java | 392 | at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858) | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/ActivityMain.java | 397 | at com.android.server.am.TaskChangeNotificationController.forAllLocalListeners(T | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/ActivityMain.java | 398 | at com.android.server.am.TaskChangeNotificationController.notifyTaskStackChanged | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/Helper.java | 1375 | E AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:971) | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/Helper.java | 2773 | at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuB | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/Helper.java | 2774 | at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:157) | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/Helper.java | 2775 | at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder. | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/Helper.java | 2776 | at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder. | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/Helper.java | 3360 | at androidx.core.hardware.fingerprint.FingerprintManagerCompat.isHardwareDetected(SourceFile:3) | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/Helper.java | 3617 | at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941) | CODE |
| CRITICAL | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 1115 | at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 1983 | at com.sun.mail.imap.IMAPFolder.open(SourceFile:61) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 1984 | at com.sun.mail.imap.IMAPFolder.open(SourceFile:1) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 1990 | at com.sun.mail.iap.Protocol.handleResult(SourceFile:8) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 1991 | at com.sun.mail.imap.protocol.IMAPProtocol.select(SourceFile:19) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 1992 | at com.sun.mail.imap.IMAPFolder.open(SourceFile:16) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2001 | at com.sun.mail.imap.IMAPFolder.open(SourceFile:61) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2002 | at com.sun.mail.imap.IMAPFolder.open(SourceFile:1) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2013 | at com.sun.mail.iap.Protocol.handleResult(SourceFile:8) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2014 | at com.sun.mail.imap.protocol.IMAPProtocol.select(SourceFile:19) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2015 | at com.sun.mail.imap.IMAPFolder.open(SourceFile:16) | CODE |
| CRITICAL | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2114 | at com.sun.mail.imap.IMAPFolder.handleIdle(SourceFile:252) | CODE |
| CRITICAL | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2115 | at com.sun.mail.imap.IMAPFolder.idle(SourceFile:7) | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2380 | at com.sun.mail.imap.IMAPFolder.open(SourceF | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2381 | at com.sun.mail.imap.IMAPFolder.open(SourceF | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2390 | at com.sun.mail.iap.Protocol.handleResult(So | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2391 | at com.sun.mail.imap.protocol.IMAPProtocol.s | CODE |
| CRITICAL⚡ | …rc/main/java/eu/faircode/email/ServiceSynchronize.java | 2392 | at com.sun.mail.imap.IMAPFolder.open(SourceF | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/StyleHelper.java | 1934 | at androidx.core.content.res.ResourcesCompat.loadFont(SourceFile:17) | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/StyleHelper.java | 1935 | at androidx.core.content.res.ResourcesCompat.loadFont(SourceFile:3) | CODE |
| CRITICAL⚡ | app/src/main/java/eu/faircode/email/StyleHelper.java | 1936 | at androidx.core.content.res.ResourcesCompat.getFont(SourceFile:2) | CODE |
| CRITICAL | …p/src/main/java/eu/faircode/email/FixedScrollView.java | 94 | at com.android.internal.policy.DecorView.onLayout(DecorView.java:889) | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/Core.java | 2837 | 06-21 10:02:38.035 9927 10024 E fairemail: at com.sun.mail.imap.IMAPStore.newIMAPFolder(Source | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/Core.java | 2838 | 06-21 10:02:38.035 9927 10024 E fairemail: at com.sun.mail.imap.DefaultFolder.listSubscribed(S | CODE |
| CRITICAL | app/src/main/java/eu/faircode/email/Core.java | 3816 | at com.sun.mail.pop3.POP3Message.loadHeaders(SourceFile:15) | CODE |
| 108 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | app/src/extra/java/eu/faircode/email/Bimi.java | 241 | // https://datatracker.ietf.org/doc/html/rfc3709#page-6 | COMMENT |
| LOW | app/src/main/java/androidx/emoji2/text/EmojiCompat.java | 561 | @SuppressWarnings("GuardedBy") // same rationale as double-check lock | COMMENT |
| LOW | …/androidx/recyclerview/selection/SelectionTracker.java | 781 | ResetManager<K> resetMgr = new ResetManager<>(); | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/MessageHelper.java | 381 | // Flags | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/MessageHelper.java | 3201 | // By-domain = "BY" FWS Extended-Domain CFWS | COMMENT |
| LOW | …/main/java/eu/faircode/email/AlarmManagerCompatEx.java | 41 | try { | COMMENT |
| LOW | …p/src/main/java/eu/faircode/email/EditTextCompose.java | 801 | } | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/EmailProvider.java | 761 | // <socketType>SSL</socketType> | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/Core.java | 641 | // com.sun.mail.iap.BadCommandException: BAD [TOOBIG] Message too large | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/Core.java | 661 | // Fetch: BAD Error in IMAP command FETCH: Invalid messageset (n.nnn + n .nnn secs). | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/Core.java | 681 | // Move: NO mailbox selected READ-ONLY | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/Core.java | 701 | // Add: NO [OVERQUOTA] Quota exceeded (mailbox for user is full) (n.nnn + n.nnn secs). | COMMENT |
| LOW | …/src/main/java/eu/faircode/email/ConnectionHelper.java | 741 | static boolean[] has46(Context context) { | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/Log.java | 381 | } | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/Log.java | 401 | // at android.os.BaseBundle.initializeFromParcelLocked(BaseBundle.java:273) | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/Log.java | 1581 | return null; | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/EntityIdentity.java | 281 | json.put("unicode", unicode); | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/EmailService.java | 181 | // can be configured in the range 1024 to 16384. | COMMENT |
| LOW | app/src/main/java/eu/faircode/email/ApplicationEx.java | 341 | WorkerSync.init(this); | COMMENT |
| LOW | …c/main/java/eu/faircode/email/FragmentDialogPrint.java | 481 | PrintDocumentAdapter adapter = printWebView.createPrintDocumentAdapter(jobName); | COMMENT |
| LOW | app/src/main/jni/cld_3/protos/task_spec.pb.h | 1 | // Generated by the protocol buffer compiler. DO NOT EDIT! | COMMENT |
| LOW | app/src/main/jni/cld_3/protos/task_spec.pb.h | 21 | COMMENT | |
| LOW | app/src/main/jni/cld_3/protos/sentence.pb.h | 1 | // Generated by the protocol buffer compiler. DO NOT EDIT! | COMMENT |
| LOW | app/src/main/jni/cld_3/protos/sentence.pb.h | 21 | COMMENT | |
| LOW | app/src/main/jni/cld_3/protos/feature_extractor.pb.h | 1 | // Generated by the protocol buffer compiler. DO NOT EDIT! | COMMENT |
| LOW | app/src/main/jni/cld_3/protos/feature_extractor.pb.h | 21 | COMMENT | |
| LOW | app/src/main/jni/cld_3/src/feature_types.h | 21 | #include <algorithm> | COMMENT |
| LOW | app/src/main/jni/cld_3/src/feature_types.h | 61 | COMMENT | |
| LOW | app/src/main/jni/cld_3/src/feature_types.h | 121 | }; | COMMENT |
| LOW | …/src/main/jni/cld_3/src/language_identifier_features.h | 21 | #include "feature_extractor.h" | COMMENT |
| LOW | …/src/main/jni/cld_3/src/language_identifier_features.h | 41 | FeatureValue GetDomainSize() const override; | COMMENT |
| LOW | …/src/main/jni/cld_3/src/language_identifier_features.h | 81 | // in the input). Otherwise, weighs each unique ngram by (ngram count) / | COMMENT |
| LOW | app/src/main/jni/cld_3/src/casts.h | 21 | #ifndef CASTS_H_ | COMMENT |
| LOW | app/src/main/jni/cld_3/src/casts.h | 41 | // int i = * reinterpret_cast<int*>(&f); // WRONG | COMMENT |
| LOW | app/src/main/jni/cld_3/src/casts.h | 61 | // | COMMENT |
| LOW | app/src/main/jni/cld_3/src/unicodetext.h | 1 | // Copyright (C) 2006 Google Inc. | COMMENT |
| LOW | app/src/main/jni/cld_3/src/unicodetext.h | 21 | #include <utility> | COMMENT |
| LOW | app/src/main/jni/cld_3/src/unicodetext.h | 41 | // 0x10FFFF], but UnicodeText has the additional restriction that it | COMMENT |
| LOW | app/src/main/jni/cld_3/src/fml_parser.h | 21 | // | COMMENT |
| LOW | app/src/main/jni/cld_3/src/registry.h | 21 | // | COMMENT |
| LOW | app/src/main/jni/cld_3/src/registry.h | 41 | // | COMMENT |
| LOW | app/src/main/jni/cld_3/src/workspace.h | 21 | #define WORKSPACE_H_ | COMMENT |
| LOW | app/src/main/jni/cld_3/src/float16.h | 21 | #include "base.h" | COMMENT |
| LOW | app/src/main/jni/cld_3/src/feature_extractor.h | 21 | // A feature extractor consists of a hierarchy of feature functions. Each | COMMENT |
| LOW | app/src/main/jni/cld_3/src/feature_extractor.h | 41 | #include <string> | COMMENT |
| LOW | app/src/main/jni/cld_3/src/feature_extractor.h | 121 | // The generic feature extractor is the type-independent part of a feature | COMMENT |
| LOW | app/src/main/jni/cld_3/src/feature_extractor.h | 201 | COMMENT | |
| LOW | app/src/main/jni/cld_3/src/feature_extractor.h | 321 | // OBJ: The "object" from which features are extracted; e.g., a sentence. This | COMMENT |
| LOW | app/src/main/jni/cld_3/src/feature_extractor.h | 381 | // are of type NES, which may be different from the type of the parent function. | COMMENT |
| LOW | …p/src/main/jni/cld_3/src/embedding_feature_extractor.h | 21 | #include <vector> | COMMENT |
| LOW | app/src/main/jni/cld_3/src/nnet_language_identifier.h | 21 | #include "base.h" | COMMENT |
| LOW | app/src/main/jni/cld_3/src/nnet_language_identifier.h | 81 | // bytes and max_num_bytes_. If N is less than min_num_bytes_ long, then this | COMMENT |
| LOW | app/src/main/jni/cld_3/src/nnet_language_identifier.h | 161 | ContinuousBagOfNgramsFunction ngram_function_; | COMMENT |
| LOW | app/src/main/jni/cld_3/src/relevant_script_feature.h | 21 | #include "sentence_features.h" | COMMENT |
| LOW | app/src/main/jni/cld_3/src/embedding_network_params.h | 141 | // are treated as repeated fields with 0 or 1 instances. As such, we have | COMMENT |
| LOW | app/src/main/jni/cld_3/src/embedding_network.h | 21 | #include "embedding_network_params.h" | COMMENT |
| LOW | app/src/main/jni/cld_3/src/base.h | 41 | #define CLD3_DISALLOW_COPY_AND_ASSIGN(TypeName) \ | COMMENT |
| LOW | app/src/main/jni/cld_3/src/base.h | 81 | (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)) | COMMENT |
| LOW | app/src/main/jni/cld_3/src/script_span/stringpiece.h | 1 | // Copyright 2013 Google Inc. All Rights Reserved. | COMMENT |
| LOW | app/src/main/jni/cld_3/src/script_span/port.h | 1 | // Copyright 2013 Google Inc. All Rights Reserved. | COMMENT |
| 94 more matches not shown… | ||||
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | …dx/recyclerview/selection/DefaultSelectionTracker.java | 363 | // representation of it. But there are some nuanced areas cases where | COMMENT |
| MEDIUM | …idx/recyclerview/selection/GestureSelectionHelper.java | 152 | // Essentially, since this means all gesture movement is over, reset everything and apply | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| HIGH | FAQ.md | 1489 | If you can't solve the problem, [please contact me](#get-support), and I'll explain how to send the debug info for a pro | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | app/src/main/res/layout/include_message_addresses.xml | 364 | android:text="user@example.org" | CODE |
| LOW | decrypt/purify.min.js | 2 | !function(e,t){"object"==typeof exports&&"undefined"!=typeof module?module.exports=t():"function"==typeof define&&define | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | app/src/main/java/javax/mail/internet/MimeBodyPart.java | 1690 | static class MimePartDataHandler extends DataHandler { | CODE |
| LOW | app/src/main/java/javax/activation/DataHandler.java | 69 | public class DataHandler /*implements Transferable*/ { | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | app/src/main/java/javax/mail/package.html | 67 | Don't forget to see the | CODE |