http://code.google.com/p/k9mail/issues/detail?id=2682

mark multiple mails as SPAM

res/layout/message_list.xml

@@ -30,6 +30,13 @@
             android:layout_weight="1"
             android:src="@drawable/ic_button_delete"
         />
+        <ImageButton
+            android:id="@+id/batch_spam_button"
+            android:layout_width="0dip"
+            android:layout_height="fill_parent"
+            android:layout_weight="1"
+            android:src="@drawable/ic_button_spam"
+        />
         <ImageButton
             android:id="@+id/batch_flag_button"
             android:layout_width="0dip"

src/com/fsck/k9/activity/MessageList.java

@@ -312,9 +312,14 @@ public class MessageList
     private boolean mCheckboxes = true;
     private int mSelectedCount = 0;
 
+    /**
+     * Area with buttons visible when multiple
+     * mails are marked.
+     */
     private View mBatchButtonArea;
     private ImageButton mBatchReadButton;
     private ImageButton mBatchDeleteButton;
+    private ImageButton mBatchSpamButton;
     private ImageButton mBatchFlagButton;
     private ImageButton mBatchDoneButton;
 
@@ -900,10 +905,13 @@ public class MessageList
         mBatchReadButton.setOnClickListener(this);
         mBatchDeleteButton = (ImageButton) findViewById(R.id.batch_delete_button);
         mBatchDeleteButton.setOnClickListener(this);
+        mBatchSpamButton = (ImageButton) findViewById(R.id.batch_spam_button);
+        mBatchSpamButton.setOnClickListener(this);
         mBatchFlagButton = (ImageButton) findViewById(R.id.batch_flag_button);
         mBatchFlagButton.setOnClickListener(this);
         mBatchDoneButton = (ImageButton) findViewById(R.id.batch_done_button);
 
+
         mBatchDoneButton.setOnClickListener(this);
 
         // Gesture detection
@@ -2960,6 +2968,16 @@ public class MessageList
             Animation animation = AnimationUtils.loadAnimation(this, R.anim.footer_appear);
             animation.setAnimationListener(this);
             mBatchButtonArea.startAnimation(animation);
+
+            
+    		// hide spam button if there is no spam folder
+            if (mAccount != null) {
+            	String folderName = mAccount.getSpamFolderName();
+            	if (K9.FOLDER_NONE.equalsIgnoreCase(folderName)
+            			|| !mController.isMoveCapable(mAccount)) {
+            		mBatchSpamButton.setVisibility(View.GONE);
+            	}
+            }
         }
     }
 
@@ -3065,6 +3083,7 @@ public class MessageList
     {
         boolean newState = false;
         List<Message> messageList = new ArrayList<Message>();
+        // messages to be removed from the view
         List<MessageInfoHolder> removeHolderList = new ArrayList<MessageInfoHolder>();
 
         if (v == mBatchDoneButton)
@@ -3092,6 +3111,10 @@ public class MessageList
                     {
                         removeHolderList.add(holder);
                     }
+                    else if (v == mBatchSpamButton)
+                    {
+                        removeHolderList.add(holder);
+                    }
                     else if (v == mBatchFlagButton)
                     {
                         holder.flagged = newState;
@@ -3114,6 +3137,17 @@ public class MessageList
                 mSelectedCount = 0;
                 toggleBatchButtons();
             }
+            else if (v == mBatchSpamButton)
+            {
+                String folderName = mAccount.getSpamFolderName();
+                if (K9.FOLDER_NONE.equalsIgnoreCase(folderName))
+                {
+                    return;
+                }
+                mController.moveMessages(mAccount, mCurrentFolder.name, messageList.toArray(EMPTY_MESSAGE_ARRAY), folderName, null);
+                mSelectedCount = 0;
+                toggleBatchButtons();
+            }
             else
             {
                 mController.setFlag(messageList.toArray(EMPTY_MESSAGE_ARRAY), (v == mBatchReadButton ? Flag.SEEN : Flag.FLAGGED), newState);