Added algorithm remark

app/src/main/res/layout/fragment_options_encryption.xml

@@ -308,6 +308,17 @@
                     app:layout_constraintStart_toStartOf="parent"
                     app:layout_constraintTop_toBottomOf="@id/tvEncryptAlgoSmime" />
 
+                <eu.faircode.email.FixedTextView
+                    android:id="@+id/tvAlgoHint"
+                    android:layout_width="wrap_content"
+                    android:layout_height="wrap_content"
+                    android:layout_marginTop="12dp"
+                    android:text="@string/title_advanced_remark_algo"
+                    android:textAppearance="@style/TextAppearance.AppCompat.Small"
+                    android:textStyle="italic"
+                    app:layout_constraintStart_toStartOf="parent"
+                    app:layout_constraintTop_toBottomOf="@id/spEncryptAlgoSmime" />
+
                 <androidx.appcompat.widget.SwitchCompat
                     android:id="@+id/swCheckCertificate"
                     android:layout_width="0dp"
@@ -317,7 +328,7 @@
                     android:text="@string/title_advanced_check_certificate"
                     app:layout_constraintEnd_toEndOf="parent"
                     app:layout_constraintStart_toStartOf="parent"
-                    app:layout_constraintTop_toBottomOf="@id/spEncryptAlgoSmime"
+                    app:layout_constraintTop_toBottomOf="@id/tvAlgoHint"
                     app:switchPadding="12dp" />
 
                 <Button

app/src/main/res/values/strings.xml

@@ -587,6 +587,10 @@
     <string name="title_advanced_encrypt_subject">Encrypt subject</string>
     <string name="title_advanced_sign_algo">Signature algorithm</string>
     <string name="title_advanced_encrypt_algo">Encryption algorithm</string>
+    <string name="title_advanced_remark_algo">
+        Please be aware that not all email clients support all algorithms.
+        The default algorithms SHA256 and AES128 are commonly supported.
+    </string>
     <string name="title_advanced_check_certificate">Check public key on sending</string>
     <string name="title_advanced_manage_certificates">Manage public keys</string>
     <string name="title_advanced_import_key">Import private key</string>