SPAMfighter - SPAMfighter and Microsoft have built the strongest and most effective anti spam filter for Outlook, Windows Live Mail, Outlook Express & Thunderbird
Numverify - Global phone number validation and lookup API
Spamihilator - The free Anti-Spam-Filter Spamihilator removes more than 98% of spam mails before they even get into your inbox.
Antideo - Email, IP address and phone number validation API service
Mailwasher - Over 8 million people use MailWasher as their spam filter
RealValidito - Phone Validator | Free Phone Number Validation & Phone Number Lookup Service | Realvalidito