BizTalk Server accepts timestamps only in the YYYYMMddHHmmss format. When an FTP server responds by using milliseconds as part of the YYYYMMddHHmmss.fff format, you may receive the following error message:
"TimeStamp retrieval failed. Ensure that FTP server supports MDTM command. Server message: “String was not recognized as a valid DateTime.” error and disable the receive location.