Error about CreateItem operation with attachment - attachment

Question

I meet a trouble when using EWS javascript API to send email with CreateItem operation.
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages">
<soap:Header>
<t:RequestServerVersion Version="Exchange2010" />
</soap:Header>
<soap:Body>
<m:CreateItem MessageDisposition="SendAndSaveCopy">
<m:SavedItemFolderId>
<t:DistinguishedFolderId Id="drafts" />
</m:SavedItemFolderId>
<m:Items>
<t:Message>
<t:Subject>Test</t:Subject>
<t:Body BodyType="Text">
Test
</t:Body>
<t:Attachments>
<t:ItemAttachment>
<t:Name>Attached Message Item</t:Name>
<t:Message>
<t:Subject></t:Subject>
<t:Body BodyType="Text">Test</t:Body>
<t:ToRecipients>
<t:Mailbox>
<t:EmailAddress>sunt#domain.com</t:EmailAddress>
</t:Mailbox>
</t:ToRecipients>
</t:Message>
</t:ItemAttachment>
</t:Attachments>
<t:ToRecipients>
<t:Mailbox>
<t:EmailAddress>sunt#domain.com</t:EmailAddress>
</t:Mailbox>
</t:ToRecipients>
</t:Message>
</m:Items>
</m:CreateItem>
</soap:Body>
</soap:Envelope>
And after executing the service request, the response status is succeeded, but the response value indicates there's an error:
<?xml version="1.0" encoding="utf-8"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Header>
<h:ServerVersionInfo MajorVersion="15" MinorVersion="0" MajorBuildNumber="847" MinorBuildNumber="40" Version="V2_8" xmlns:h="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>
</s:Header>
<s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<m:CreateItemResponse xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
<m:ResponseMessages>
<m:CreateItemResponseMessage ResponseClass="Error">
<m:MessageText>Set action is invalid for property.</m:MessageText>
<m:ResponseCode>ErrorInvalidPropertySet</m:ResponseCode>
<m:DescriptiveLinkKey>0</m:DescriptiveLinkKey>
<m:MessageXml>
<t:FieldURI FieldURI="item:Attachments"/>
</m:MessageXml>
<m:Items/>
</m:CreateItemResponseMessage>
</m:ResponseMessages>
</m:CreateItemResponse>
</s:Body>
</s:Envelope>
Can't the CreateItem operation execute with attachment? Or how to succeed with it?