Attachment.Size Property (Outlook)
Returns a Long indicating the size (in bytes) of the attachment. Read-only.
Syntax
expression .Size
expression A variable that represents an Attachment object.
Remarks
This information may not always be available for attachments. For example, on an S/MIME message, the actual attachment sizes are unknown until the attachment is extracted. In cases where the attachment size cannot be determined, this property returns 0.