The mail header entry at the point it leaves FedEx's systems and enters my website is:

    Received: from pvma00057.prod.fedex.com ([204.135.8.98]:61625 helo=mx28.infosec.fedex.com)
	by gator4118.hostgator.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256)
	(Exim 4.87)
	(envelope-from <prvs=1370ad99fd=bounce@nds.fedex.com>)
	id 1dWn4C-00092V-Dd
	for nagle@animats.com; Sun, 16 Jul 2017 12:10:48 -0500
    DKIM-Signature: v=1; a=rsa-sha256; d=fedex.com; s=edc; c=relaxed/relaxed;
	q=dns/txt; i=@fedex.com; t=1500225037;
	h=From:Sender:Reply-To:Subject:Date:Message-ID:To;
	bh=M2wd7ncO9bsu5aQpoaGPtLYIjzi/OkxO+5qgmnqO1D4=;
	b=ktUTxDShfkakjcLd2BEwRVC4X4ItHdPYvR+Dqyj6oiWPWrsuWA98jHqIssipCXHa
	XsPn72sxMnWIlwy0LLC3r2WGTUBHg7afy0K804QLQ2ztSHr7CnMZ4jFh0O6A9ElQ
	16twStNpiG9XBF4Gho08WHg+EUrKSnTqPwknnhOg+9BVyKZLsQhsGAk1Bl/Vgu9z
	55RxPd3VjDlAM04i+sZZaLLTX3TLA8jbMHNgZpwx01j6/whY2RVktfMYvmJZo3n9
	6XVJTcUVA3QiXb32Ps9OwGpOZQMSR0EKGrXSEUyk8YEGDZmFkZOgy6cUZBuzKRXs
	yPqdVtE4gHvuck8T5nrllg==;
    X-AuditID: cc870862-345fb700000012f5-3f-596b9e0d6fb1

That looks OK. Unless FedEx has an open mail forwarder, a break-in at "pvma00057.prod.fedex.com", or DNS trouble, that's from FedEx.