Error message when you publish a large custom Outlook form that contains many controls or user-defined fields: "Unable to successfully publish the form due to a MAPI error"

You create a large custom Microsoft Outlook form that contains many controls or user-defined fields. When you try to publish the form, you receive an error message that resembles the following: Note The error message will also reference a TMP file that is located in the Windows folder that stores temporary files.

This is a limitation of publishing forms on a computer that is running Microsoft Windows Millennium Edition (Windows Me), Windows 98, or Windows 95. This problem typically occurs when the form contains more than 300 controls or user-defined fields.

To work around this problem, use one of the following methods:

• When you publish the form, use a computer that is running Microsoft Windows Server 2003, Windows XP, Windows 2000, or Windows NT.
• Redesign the forms solution so that the solution uses multiple forms instead of one large form.
• Consider using a database management program such as Microsoft Access to store large amounts of data.
• As a last resort, reduce the number of fields on the form. You can do this by using one Outlook field to store information that you would typically store in more than one field. You would then use an Item_Open event and Microsoft Visual Basic Scripting Edition (VBScript) to read the single field and parse the data. You could also use an Item_Write event to concatenate the data and save it back to the single field.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Computers that are running Windows Millennium Edition, Windows 98, or Windows 95 will not have a problem using the large form that you have published on a computer that is running Windows Server 2003, Windows XP, Windows 2000, or Windows NT. The problem only occurs during the publishing process. The temporary file that is created is in the same format as a standard Windows .ini file. However, the size of the temporary file exceeds 64 kilobytes (KB). Windows Millennium Edition, Windows 98, or Windows 95 only support .ini files that are smaller than 64 KB.

For more information about limitations that are related to the number of fields or controls on a custom Outlook form, click the following article number to view the article in the Microsoft Knowledge Base: