Blocking the "Reply to All" option

Sometimes, when you send messages to a group of people, you do not want the recipients to reply to everybody that was on the list ("Reply to all" option). It is very useful when you send newsletters, advertisements or important updates, and you wish your recipients not to reply and block the mail flow. Especially, when your message has attachments or is rich in graphic elements like pictures and logos. When users reply or forward to a group they fill the mailbox unnecessarily or slow down the mail servers. By default, Microsoft Outlook doesn’t have any settings to let you block the "Reply to all" option. However, you can create your own form that you will use when sending group messages. This article explains how to do it

In your Microsoft Outlook:
1. Choose Tools, Forms, Design a Form.
2. On the Standard Form Library choose Message and then Open (Fig.1).

Fig.1 Window with available forms to edit. 

3. In the new window go to Actions tab. Here, choose the row Reply to all and highlight it (Fig.2).

Fig.2 You can edit various options in your form. In our example we will disable "Reply to All" option.

4. When this tab is highlighted, click Properties button on the bottom. In the new window uncheck the Enable setting in the top right corner and then click OK (Fig.3).

Fig.3 Uncheck the Enabled option on the Action properties.

5.  Now, go to Properties tab, choose option Send Form Definition with Item. A warning with a massage will show up explaining that this practice is not recommended. Accept with OK (Fig.4).

Fig.4 A warning message that suggests it is not a good idea. 

6. Choose button Publish on Ribbon and then Publish Form As.
7. A new window will be displayed where we can give a name to our new form. It can be your choice but no spaces included in the title (e.g. ReplyToAll_Disabled). Make sure that you save your form in the Personal Form Library (this name should be next to the Look in field). When you choose the name, click Publish (Fig.5).

Fig. 5 Providing a name for your new form. 

8. You come back to the main window that you can close now. When Outlook asks you a message about saving changes, click OK.

Your form is ready to use. It will not work for every new massage you create because it is not set as default form. Every time you want to use it for your new messages, in Outlook, go to Tools, Forms, Choose a form. A new window will be displayed. By default, Organizational Forms Library will be seen. From the drop-down list next to Look in and choose Personal Forms Library. Now you can see your new created form (in our example ReplyToAll_Disabled) and click Open (Fig.6).

Fig.6 Selecting you new form from the list in Personal Forms Library.

 Now you can create and send a new massage to a group of recipients. If they use Outlook as their mail client the option, "Reply to All" will not be available and they will not reply to the group of recipients, only to the sender. When they try to reply to all, Outlook will show a warning and will not allow to perform this action (Fig.7).

Fig.7 A warning message for the user