с security update (из-за которого у тебя проблеммы) на vba через MAPI никак
далее выдержки из msdn
Item.Send
When you run a program that uses the Outlook object model to call the Send method, you receive a warning message. This warning message tells you that a program is trying to send mail on your behalf and asks if you want to allow the message to be sent. The warning message contains both a Yes and a No button; however, the Yes button is not available until five seconds have passed since the warning message appeared. You can dismiss the warning message immediately if you click No. When you click No, the Send method returns an E_FAIL error in the C or C++ programming languages.

Avoiding the Security Features
The e-mail security features affect all custom solutions that use the Outlook object model, CDO, or Simple MAPI, even if they are digitally signed. This includes the following:

Outlook custom forms that are published to any folder or forms library, including the Organizational Forms Library

Outlook COM Add-ins

Outlook Visual Basic for Applications

Any other type of development project that uses the Outlook object model, CDO or Simple MAPI

As a developer, you have various options when you try to avoid the security features. To summarize your typical options depending on where you are developing your solution:
Outlook custom forms: Publish forms so that they are not one-off forms, or use the administrator features to enable VBScript code in one-off forms to run.

Outlook Visual Basic for Applications: Use the administrator features to disable object model restrictions, or convert your Visual Basic for Applications code to a COM Add-in, and then register it by using the administrator form.

COM add-ins: COM add-ins can be trusted if an administrator registers them by using the administrator form. However, when you are using a COM add-in, only the Outlook object model is exempted; the CDO object model will still generate warnings.

You cannot trust COM add-ins in Outlook 2000. This was a feature that was added to the Outlook 2002 version of the administrator form.

Automating the Outlook or CDO object models: Use the administrator features to disable object model restrictions.

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ссылки по теме:
http://support.microsoft.com/default.aspx?scid=kb;en-us;290500