OnWebChange
Track web page changes in any web page daily for free users, every 30 minutes for paid users - no RSS or Atom required. Receive notifications via email, Instant Message...
Description by owner: "Monitors your website/server for free, 30 seconds interval. Complete delivery test for e-mail servers (sends an e-mail, waits for it to arrive). Alerts via SMS/e-mail. Worldwide network.
description by owner:"monitors your website/server for free, 30 seconds interval. complete delivery test for email servers (sends an email, waits for it to arrive). alerts via sms/email. worldwide network.
write your own scripts and execute when servers goes down (and up).
10% of all purchases are donated to charity of your choise".
alternativein.com comments:the free account can check for keywords and monitor with a frequency of once per minute (the best among free plans).
Productivity Developer Tools Networking and Admin Online Services
website-monitoring cloud-monitoring server-monitoring uptime-monitoring web-monitoring email-monitoring