When an .xlsx attachment that's created by Export-Excel is sent through the Edge Transport server that has Attachment Filtering agent enabled in Microsoft Exchange Server 2019 or Exchange Server 2016, the attachment is treated as bad zip file.
When parsing the data descriptor record of the attachment, the attachment is treated as bad zip file. Currently, when parsing data descriptor record, the signature (0x08074b50) is checked only when compressed size in local file header (LFH) is 0. However, for an .xlsx attachment generated through Export-Excel, compressed size is present in LFH, and still it has data descriptor record with the signature. In this case, the parsing fails, and the attachment is treated as bad zip file.
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