Check the Programmatic Access settings under the Trust Center in Outlook.
One way around this issue in the past was to use the Express ClickYes utility downloadable from
http://www.contextmagic.com/express-clickyes/free-version.htm
Another alternative if you export you data source to Excel would be to use the Merge with Attachments (attachments are not mandatory) utility on the MergeTools – 20140218.dotm Add-in that I created that you can download from the following page of my One Drive:
The file needs to be saved in the Word Startup folder. In Windows XP the default location for that folder is
C:\Documents and Settings[User Name]\Application Data\Microsoft\Word\STARTUP
In Windows Vista and Windows 7, 8 or 8.1 it is
C:\Users[User Name]\AppData\Roaming\Microsoft\Word\STARTUP
When that has been done and Word is started\re-started, the tab shown below will be added to the Ribbon:
One thing to note is that the field names in the data source must contain only alphanumeric characters (No @,#,$,%,&,(,), etc) and the field names must not start with a numeric character (0-9).
You may also want to download:
- the Merging with Attachments document that is also on that page which explains how the system is used. It is not actually necessary to have separate attachments as the facility can be used to send just the documents created by the merge itself as attachments, either as the body of the message itself or in the form of Word files or .pdf files.
- the Mail Merging with Charts document that is also on that page. That document explains how you must set up the Excel Data Source and the Mail Merge Main document to be able to execute a merge with a Chart that is unique to each record in the data source.
- the Using the Many to One Facility document that describes how to use that facility.