block server entries in AccountSetupIncoming.java and AccountSetupOutgoing.java that are not valid domain names.

src/com/fsck/k9/Utility.java

@@ -10,6 +10,7 @@ import java.util.Date;
 import com.fsck.k9.codec.binary.Base64;
 
 import android.text.Editable;
+import android.widget.EditText;
 import android.widget.TextView;
 
 public class Utility {
@@ -76,10 +77,21 @@ public class Utility {
         return view.getText() != null && view.getText().length() > 0;
     }
     
+
     public static boolean requiredFieldValid(Editable s) {
         return s != null && s.length() > 0;
     }
 
+    public static boolean domainFieldValid(EditText view) {
+		if (view.getText() != null) {
+			String s = view.getText().toString();
+			if (s.matches("^([a-zA-Z0-9]([a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9])?\\.)+[a-zA-Z]{2,6}$")) {
+				return true;
+			}
+		}
+		return false;
+	}
+
     /**
      * Ensures that the given string starts and ends with the double quote character. The string is not modified in any way except to add the
      * double quote character to start and end if it's not already there.
@@ -173,4 +185,5 @@ public class Utility {
 //            }
 //        }
     }
+
 }

src/com/fsck/k9/activity/setup/AccountSetupIncoming.java

@@ -5,6 +5,8 @@ import java.net.URI;
 import java.net.URISyntaxException;
 
 import android.app.Activity;
+import android.app.AlertDialog;
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
 import android.text.Editable;
@@ -254,7 +256,7 @@ public class AccountSetupIncoming extends Activity implements OnClickListener {
         mNextButton
                 .setEnabled(Utility.requiredFieldValid(mUsernameView)
                         && Utility.requiredFieldValid(mPasswordView)
-                        && Utility.requiredFieldValid(mServerView)
+                        && Utility.domainFieldValid(mServerView)
                         && Utility.requiredFieldValid(mPortView));
         Utility.setCompoundDrawablesAlpha(mNextButton, mNextButton.isEnabled() ? 255 : 128);
     }
@@ -326,6 +328,7 @@ public class AccountSetupIncoming extends Activity implements OnClickListener {
 
     	mAccount.setDeletePolicy((Integer)((SpinnerOption)mDeletePolicyView.getSelectedItem()).value);
     	AccountSetupCheckSettings.actionCheckSettings(this, mAccount, true, false);
+
     }
 
     public void onClick(View v) {

src/com/fsck/k9/activity/setup/AccountSetupOutgoing.java

@@ -222,7 +222,7 @@ public class AccountSetupOutgoing extends Activity implements OnClickListener,
     private void validateFields() {
         mNextButton
                 .setEnabled(
-                        Utility.requiredFieldValid(mServerView) && 
+                        Utility.domainFieldValid(mServerView) && 
                         Utility.requiredFieldValid(mPortView) && 
                         (!mRequireLoginView.isChecked() || 
                                 (Utility.requiredFieldValid(mUsernameView) &&