This service is probably not very useful for manual use, however it has pretty good API (without any limits)!
It has two major endpoints:
http://mail.1488.me/api/list/<md5 of inbox> to get list of received messages Example: http://mail.1488.me/api/list/f52ffcffdcc0137284eb812e39d15ce9 for firstname.lastname@example.org
http://mail.1488.me/storage/<md5 of inbox>/<message ID received from /api/list query> to get the received message Example: http://mail.1488.me/storage/f52ffcffdcc0137284eb812e39d15ce9/9b2854238441fc5cbfa0700f2251cfe7 for email@example.com and message with ID of 9b2854238441fc5cbfa0700f2251cfe7
All messages are stored for around 10 minutes. There are no limits at all of using the API.