MxToolBox is described as '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' and is a Uptime Monitor service in the network & admin category. There are more than 50 alternatives to MxToolBox, not only websites but also apps for a variety of platforms, including SaaS, Windows, Linux and Self-Hosted apps. The best MxToolBox alternative is Domain Digger, which is both free and Open Source. Other great sites and apps similar to MxToolBox are Pingdom, HetrixTools, MailAegis and Klaxel.
DNS Check is an application which compares the DNS records that you enter to what nameservers are returning in response to queries. If there's an issue, DNS Check will notify you, and enable you to quickly identify what it is. Issues which can be detected include:
Statusdroid operates a worldwide network of servers which checks your website every 30 seconds from over 15 worldwide locations.
DomainCat monitors SSL certificates and domain health for sysadmins and managed service providers. Get escalating expiry alerts, full DNS/SPF/DMARC checks, and a Grafana-compatible API — all without agents or firewall changes.
