This is quite handy. Either had to provide your email addy to a website to register software or download a document. If you are like me and are keen to avoid spam you will really reluctant to do this.
Pookmail.com is the answer.
Go to the website. Use an email address like email@example.com and your email will be displayed (to all who enter this address) for 24 hrs.
Just enough time to click the confirmation link or whatever. After 24 hours the address is deleted.
Costs nothing. Give it ago.