diff --git a/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java b/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
index d8c48ed7b5..b3399d2114 100644
--- a/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
+++ b/app/src/main/java/eu/faircode/email/BoundaryCallbackMessages.java
@@ -42,6 +42,7 @@ import com.sun.mail.imap.protocol.SearchSequence;
 import java.io.File;
 import java.io.IOException;
 import java.io.Serializable;
+import java.lang.reflect.Constructor;
 import java.nio.charset.StandardCharsets;
 import java.text.Normalizer;
 import java.util.ArrayList;
@@ -66,6 +67,7 @@ import javax.mail.search.BodyTerm;
 import javax.mail.search.ComparisonTerm;
 import javax.mail.search.FlagTerm;
 import javax.mail.search.FromStringTerm;
+import javax.mail.search.NotTerm;
 import javax.mail.search.OrTerm;
 import javax.mail.search.ReceivedDateTerm;
 import javax.mail.search.RecipientStringTerm;
@@ -192,6 +194,8 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
         DB db = DB.getInstance(context);
 
         int found = 0;
+        if (criteria.isExpression())
+            return found;
 
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
         boolean fts = prefs.getBoolean("fts", false);
@@ -677,6 +681,17 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                     with_size != null);
         }
 
+        boolean isExpression() {
+            if (this.query == null)
+                return false;
+
+            for (String w : this.query.trim().split("\\s+"))
+                if (w.length() > 1 && "+-?".indexOf(w.charAt(0)) >= 0)
+                    return true;
+
+            return false;
+        }
+
         SearchTerm getTerms(boolean utf8, Flags flags, String[] keywords) {
             List<SearchTerm> or = new ArrayList<>();
             List<SearchTerm> and = new ArrayList<>();
@@ -689,6 +704,39 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                             .replaceAll("[^\\p{ASCII}]", "");
                 }
 
+                List<String> word = new ArrayList<>();
+                List<String> plus = new ArrayList<>();
+                List<String> minus = new ArrayList<>();
+                List<String> opt = new ArrayList<>();
+                StringBuilder sb = new StringBuilder();
+                for (String w : search.trim().split("\\s+")) {
+                    if (sb.length() > 0)
+                        sb.append(' ');
+
+                    if (w.length() > 1 && w.startsWith("+")) {
+                        plus.add(w.substring(1));
+                        sb.append(w.substring(1));
+                    } else if (w.length() > 1 && w.startsWith("-")) {
+                        minus.add(w.substring(1));
+                        sb.append(w.substring(1));
+                    } else if (w.length() > 1 && w.startsWith("?")) {
+                        opt.add(w.substring(1));
+                        sb.append(w.substring(1));
+                    } else {
+                        word.add(w);
+                        sb.append(w);
+                    }
+                }
+
+                if (plus.size() + minus.size() + opt.size() > 0) {
+                    search = sb.toString();
+                    Log.i("SEARCH word=" + TextUtils.join(",", word));
+                    Log.i("SEARCH plus=" + TextUtils.join(",", plus));
+                    Log.i("SEARCH minus=" + TextUtils.join(",", minus));
+                    Log.i("SEARCH opt=" + TextUtils.join(",", opt));
+                    Log.i("SEARCH full=" + search);
+                }
+
                 // Yahoo! does not support keyword search, but uses the flags $Forwarded $Junk $NotJunk
                 boolean hasKeywords = false;
                 for (String keyword : keywords)
@@ -704,12 +752,31 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
                     or.add(new RecipientStringTerm(Message.RecipientType.CC, search));
                     or.add(new RecipientStringTerm(Message.RecipientType.BCC, search));
                 }
+
                 if (in_subject)
-                    or.add(new SubjectTerm(search));
+                    if (plus.size() + minus.size() + opt.size() == 0)
+                        or.add(new SubjectTerm(search));
+                    else
+                        try {
+                            or.add(construct(word, plus, minus, opt, SubjectTerm.class));
+                        } catch (Throwable ex) {
+                            Log.e(ex);
+                            or.add(new SubjectTerm(search));
+                        }
+
                 if (in_keywords && hasKeywords)
                     or.add(new FlagTerm(new Flags(MessageHelper.sanitizeKeyword(search)), true));
+
                 if (in_message)
-                    or.add(new BodyTerm(search));
+                    if (plus.size() + minus.size() + opt.size() == 0)
+                        or.add(new BodyTerm(search));
+                    else
+                        try {
+                            or.add(construct(word, plus, minus, opt, BodyTerm.class));
+                        } catch (Throwable ex) {
+                            Log.e(ex);
+                            or.add(new BodyTerm(search));
+                        }
             }
 
             if (with_unseen && flags.contains(Flags.Flag.SEEN))
@@ -739,6 +806,39 @@ public class BoundaryCallbackMessages extends PagedList.BoundaryCallback<TupleMe
             return term;
         }
 
+        private SearchTerm construct(
+                List<String> word,
+                List<String> plus,
+                List<String> minus,
+                List<String> opt,
+                Class<?> clazz) throws ReflectiveOperationException {
+            SearchTerm term = null;
+            Constructor<?> ctor = clazz.getConstructor(String.class);
+
+            if (word.size() > 0)
+                term = (SearchTerm) ctor.newInstance(TextUtils.join(" ", word));
+
+            for (String p : plus)
+                if (term == null)
+                    term = (SearchTerm) ctor.newInstance(p);
+                else
+                    term = new AndTerm(term, (SearchTerm) ctor.newInstance(p));
+
+            for (String m : minus)
+                if (term == null)
+                    term = new NotTerm((SearchTerm) ctor.newInstance(m));
+                else
+                    term = new AndTerm(term, new NotTerm((SearchTerm) ctor.newInstance(m)));
+
+            for (String o : opt)
+                if (term == null)
+                    term = (SearchTerm) ctor.newInstance(o);
+                else
+                    term = new OrTerm(term, (SearchTerm) ctor.newInstance(o));
+
+            return term;
+        }
+
         String getTitle(Context context) {
             List<String> flags = new ArrayList<>();
             if (with_unseen)
diff --git a/app/src/main/java/eu/faircode/email/FragmentDialogSearch.java b/app/src/main/java/eu/faircode/email/FragmentDialogSearch.java
index dae96f5881..8608e71892 100644
--- a/app/src/main/java/eu/faircode/email/FragmentDialogSearch.java
+++ b/app/src/main/java/eu/faircode/email/FragmentDialogSearch.java
@@ -295,7 +295,7 @@ public class FragmentDialogSearch extends FragmentDialogBase {
                         if (criteria.query != null && criteria.query.startsWith("raw:"))
                             new SimpleTask<EntityFolder>() {
                                 @Override
-                                protected EntityFolder onExecute(Context context, Bundle args) throws Throwable {
+                                protected EntityFolder onExecute(Context context, Bundle args) {
                                     long aid = args.getLong("account", -1);
 
                                     DB db = DB.getInstance(context);
@@ -334,6 +334,10 @@ public class FragmentDialogSearch extends FragmentDialogBase {
                                     Log.unexpectedError(getParentFragmentManager(), ex);
                                 }
                             }.execute(getContext(), getViewLifecycleOwner(), getArguments(), "search:raw");
+                        else if (criteria.isExpression() && folder > 0)
+                            FragmentMessages.search(
+                                    getContext(), getViewLifecycleOwner(), getParentFragmentManager(),
+                                    account, folder, true, criteria);
                         else
                             FragmentMessages.search(
                                     getContext(), getViewLifecycleOwner(), getParentFragmentManager(),