This is interesting. This is a list of relays with the From field matching '@ebay.'
202.64.65.129.in-addr.arpa domain name pointer gabriel.its.calpoly.edu. 204.64.65.129.in-addr.arpa domain name pointer email-gateway-michael.its.calpoly.edu. 10.193.98.140.in-addr.arpa domain name pointer ruebert.ieee.org. 23.193.98.140.in-addr.arpa domain name pointer engine.ieee.org. 55.1.41.198.in-addr.arpa domain name pointer mx01.nic.name. 56.1.41.198.in-addr.arpa domain name pointer mx02.nic.name. 34.3.41.198.in-addr.arpa domain name pointer mx04.nic.name. 35.3.41.198.in-addr.arpa domain name pointer mx05.nic.name. 199.132.22.203.in-addr.arpa domain name pointer wm-06.dcsi.net.au. 51.11.13.204.in-addr.arpa domain name pointer bellerophon.decipherinc.com. 173.52.190.206.in-addr.arpa domain name pointer smtp104.biz.mail.re2.yahoo.com. 45.66.191.209.in-addr.arpa domain name pointer mailforward101.store.mud.yahoo.com. 47.66.191.209.in-addr.arpa domain name pointer mailforward103.store.mud.yahoo.com. 48.66.191.209.in-addr.arpa domain name pointer mailforward104.store.mud.yahoo.com. 21.98.109.210.in-addr.arpa is an alias for 21.0-255.98.109.210.in-addr.arpa. 21.0-255.98.109.210.in-addr.arpa domain name pointer mail-kr1.bigfoot.com. 228.216.115.211.in-addr.arpa is an alias for 228.0-255.216.115.211.in-addr.arpa. 228.0-255.216.115.211.in-addr.arpa domain name pointer mail-kr.bigfoot.com. 150.180.144.216.in-addr.arpa is an alias for 216.144.180.150.rev.k12system.com. 216.144.180.150.rev.k12system.com domain name pointer boboshrimps.dok.org. 51.145.200.216.in-addr.arpa domain name pointer sitemail.everyone.net. 105.160.220.216.in-addr.arpa domain name pointer dickory.paonline.com. 84.244.33.216.in-addr.arpa domain name pointer sem.ebay.com. 123.161.121.59.in-addr.arpa domain name pointer 59-121-161-123.dynamic.hinet.net. 106.255.123.61.in-addr.arpa domain name pointer 61123255106.cidr.odn.ne.jp. 3.186.209.63.in-addr.arpa domain name pointer mx1.iviewer.com. 163.171.251.63.in-addr.arpa domain name pointer m1.dnsix.com. 19.14.80.63.in-addr.arpa domain name pointer mailhost.liveworld.com. 202.166.71.64.in-addr.arpa is an alias for 202.subnet192.166.71.64.in-addr.arpa. 202.subnet192.166.71.64.in-addr.arpa domain name pointer spf5.us4.outblaze.com. 138.45.48.65.in-addr.arpa domain name pointer reverse.138.45.48.65.static.ldmi.com. 5.21.134.66.in-addr.arpa domain name pointer h-66-134-21-5.hstqtx02.covad.net. 180.195.135.66.in-addr.arpa domain name pointer data.ebay.com. 11.197.135.66.in-addr.arpa domain name pointer mxpool05.ebay.com. 12.197.135.66.in-addr.arpa domain name pointer mxpool06.ebay.com. 13.197.135.66.in-addr.arpa domain name pointer mxpool07.ebay.com. 14.197.135.66.in-addr.arpa domain name pointer mxpool08.ebay.com. 15.197.135.66.in-addr.arpa domain name pointer mxpool09.ebay.com. 16.197.135.66.in-addr.arpa domain name pointer mxpool10.ebay.com. 17.197.135.66.in-addr.arpa domain name pointer mxpool11.ebay.com. 18.197.135.66.in-addr.arpa domain name pointer mxpool12.ebay.com. 19.197.135.66.in-addr.arpa domain name pointer mxpool13.ebay.com. 20.197.135.66.in-addr.arpa domain name pointer mxpool14.ebay.com. 21.197.135.66.in-addr.arpa domain name pointer mxpool15.ebay.com. 22.197.135.66.in-addr.arpa domain name pointer mxpool16.ebay.com. 23.197.135.66.in-addr.arpa domain name pointer mxpool17.ebay.com. 24.197.135.66.in-addr.arpa domain name pointer mxpool18.ebay.com. 25.197.135.66.in-addr.arpa domain name pointer mxpool19.ebay.com. 26.197.135.66.in-addr.arpa domain name pointer mxpool20.ebay.com. 27.197.135.66.in-addr.arpa domain name pointer mxpool21.ebay.com. 28.197.135.66.in-addr.arpa domain name pointer mxpool22.ebay.com. 29.197.135.66.in-addr.arpa domain name pointer mxpool23.ebay.com. 8.197.135.66.in-addr.arpa domain name pointer mxpool02.ebay.com. 198.209.135.66.in-addr.arpa domain name pointer mxsmfpool01.ebay.com. 199.209.135.66.in-addr.arpa domain name pointer mxsmfpool02.ebay.com. 200.209.135.66.in-addr.arpa domain name pointer mxsmfpool03.ebay.com. 201.209.135.66.in-addr.arpa domain name pointer mxsmfpool04.ebay.com. 202.209.135.66.in-addr.arpa domain name pointer mxsmfpool05.ebay.com. 203.209.135.66.in-addr.arpa domain name pointer mxsmfpool06.ebay.com. 204.209.135.66.in-addr.arpa domain name pointer mxsmfpool07.ebay.com. 205.209.135.66.in-addr.arpa domain name pointer mxsmfpool08.ebay.com. 206.209.135.66.in-addr.arpa domain name pointer mxsmfpool09.ebay.com. 207.209.135.66.in-addr.arpa domain name pointer mxsmfpool10.ebay.com. 208.209.135.66.in-addr.arpa domain name pointer mxsmfpool11.ebay.com. 209.209.135.66.in-addr.arpa domain name pointer mxsmfpool12.ebay.com. 210.209.135.66.in-addr.arpa domain name pointer mxsmfpool13.ebay.com. 211.209.135.66.in-addr.arpa domain name pointer mxsmfpool14.ebay.com. 212.209.135.66.in-addr.arpa domain name pointer mxsmfpool15.ebay.com. 213.209.135.66.in-addr.arpa domain name pointer mxsmfpool16.ebay.com. 214.209.135.66.in-addr.arpa domain name pointer mxsmfpool17.ebay.com. 215.209.135.66.in-addr.arpa domain name pointer mxsmfpool18.ebay.com. 216.209.135.66.in-addr.arpa domain name pointer mxsmfpool19.ebay.com. 217.209.135.66.in-addr.arpa domain name pointer mxsmfpool20.ebay.com. 218.209.135.66.in-addr.arpa domain name pointer mxsmfpool21.ebay.com. 219.209.135.66.in-addr.arpa domain name pointer mxsmfpool22.ebay.com. 220.209.135.66.in-addr.arpa domain name pointer mxsmfpool23.ebay.com. 221.209.135.66.in-addr.arpa domain name pointer mxsmfpool24.ebay.com. 142.236.165.66.in-addr.arpa domain name pointer halo.mem40now.com. 140.21.70.66.in-addr.arpa domain name pointer ian.ukinternetsites.com. 130.141.63.67.in-addr.arpa domain name pointer mail.f1networks.com. 191.85.85.68.in-addr.arpa domain name pointer c-68-85-85-191.hsd1.nj.comcast.net. 49.157.67.72.in-addr.arpa domain name pointer static-72-67-157-49.lsanca.dsl-w.verizon.net. 189.47.83.80.in-addr.arpa domain name pointer smtp1.net2000.ch. 6.96.95.80.in-addr.arpa domain name pointer mx1.b26.cz. 70.56.214.81.in-addr.arpa domain name pointer dsl.static812145670.ttnet.net.tr. 126.63.248.81.in-addr.arpa domain name pointer ACayenne-101-1-14-126.w81-248.abo.wanadoo.fr. 205.80.250.81.in-addr.arpa domain name pointer AToulouse-151-1-54-205.w81-250.abo.wanadoo.fr. 91.9.58.81.in-addr.arpa domain name pointer unlabelled-91-9-58-81.versatel.net. 156.117.243.82.in-addr.arpa domain name pointer cap31-5-82-243-117-156.fbx.proxad.net. 237.7.118.85.in-addr.arpa domain name pointer ms1.imhg.co.uk.