Pingdom web site monitoring and other infrastructure for you and instantly let you know when anything goes wrong. Measure uptime, downtime, and the performance of your website as experienced by visitors.




SMTP Diag Tool is described as 'Is used to identify and troubleshoot SMTP server problems by trying to send a message to an SMTP server while displaying all diagnostic information in realtime in a log window' and is an app in the network & admin category. There are more than 10 alternatives to SMTP Diag Tool for a variety of platforms, including Web-based, SaaS, Mac, Windows and Linux apps. The best SMTP Diag Tool alternative is Pingdom. It's not free, so if you're looking for a free alternative, you could try MxToolBox or Upzilla. Other great apps like SMTP Diag Tool are Website Monitoring by Uptime.com, intoDNS, Pingbreak and Dnsstuff.
Pingdom web site monitoring and other infrastructure for you and instantly let you know when anything goes wrong. Measure uptime, downtime, and the performance of your website as experienced by visitors.




All of your MX record, DNS, blacklist and SMTP diagnostics in one integrated tool. Input a domain name or IP Address or Host Name. Links in the results will guide you to other relevant tools and information.


Uptime.com: Real-time availability monitoring & response for preventing website downtime. Your complete website monitoring solution.




Monitor your website, server, API, application, service and get notified if your resources have some problems with availability. Upzilla notifies you in Slack, Telegram, Messenger, or by email. Works also as a public status page with subscriptions.





Pingbreak is an original and free monitoring service. Get notified through Twitter if your website is down. Pingbreak checks all of your websites each minute and alert you instantly by Direct Message (DM)



DNSstuff offers DNS tools, Network tools, Email tools, DNS reporting and IP information gathering. Explore monitoring products and free DNS tools at DNSstuff.



Netthrob runs automated verification checks on your website every three minutes from five different geographies and immediately informs you through Phone, SMS & Email when your site goes down.
Silent Down is a website uptime and performance monitoring platform, to keep an eye on your application and instantly alert you if any issues arrive.




Unlimited monitors checked from multiple location every minute. Monitor any port or setup a "heartbeat" that works well for cron jobs or any service behind a firewall. Be alerted as soon as your service is offline via email or app integration.

Uptimely simplifies monitoring the uptime of your services, alerts you to downtime, and helps you create status pages to keep your customers informed.