Our advice is to to never insert your real email address in a form on the Web because you  might get spammed. Use a disposable e-mail address instead, and you can choose from a number of services that offer them. We selected 10 of the best disposable e-mail providers we found on the Internet.

ZoEmail
“What makes ZoEmail different... is that it can block unwanted email without blocking emails from friends, colleagues and mailing lists....”
ZoEmail provides spam-free email accounts with a web-based interface and 24MB/100MB storage. Addresses are made of three parts: user name, key and domain.
Only mail sent to a valid key is allowed through to your ZoEmail Inbox.

Spamex
“Spamex provides a solid, useful, and almost feature-complete disposable email address service.” It offers unlimited disposable email addresses, to be used instead of your real one.

Emailias
Emailias adds a JavaScript button to your IE Links bar for auto-creating a new disposable address and associating it with one of your real addresses and the Web site for which you created the Emailias. You can have unlimited addresses, and the maximum size of messages can be up to 50MB.

2 Prong
2 Prong offers email addresses for one-time use. By changing the domain name frequently, 2 Prong avoids being blocked, and mail can be picked up without manual checking. “2Prong is the only no-click disposable email system. 2Prong also changes the domain every week in order to prevent the addresses from being banned.”

E4ward
E4ward is very useful disposable email service that makes it easy to prevent spam to your real email address with easily erasable aliases. E4ward lets you create aliases for multiple real email addresses. You can set up custom aliases or use random characters.

Spamgourmet
Create unlimited disposable email addresses that automatically expire after 1-20 messages. Abuse can be prevented by requiring certain words in the new address, or even a password.

Mailinator
Mailinator lets you use any email address @mailinator.com. There is no connection to your real address, so won't get spam from using Mailinator addresses. One of the cons is that all mail sent to Mailinator is made public!

GishPuppy
“GishPuppy is a free service that helps you manage all your online registrations while still keeping your identity safe on the web. GishPuppy offers disposable email addresses that automatically forward messages to your normal (private) email.”
Some of the cons are that GishPuppy does not protect your real address in replies
and you cannot make addresses expire after a certain amount of mail received.

KasMail
KasMail makes it easy to set up disposable and optionally auto-expiring email aliases with a browser bookmarklet .It is limited only to 25 disposable addresses, and address masking in replies to messages received through a KasMail alias is not available.
KasMail does not support custom domains.

MailEater
MailEater is an extremely simple disposable email address service that lets you use any @maileater.com address. Any mail received at MailEater will be kept for 4 hours.
Some of the cons are that MailEater does not allow you to write replies to messages received and you cannot protect the mail you get at MailEater with a password so anybody can see it!

written by Cristian L.