Cloudsome not only lets you check for presence of a string on a web page, but also when checking a remote port. This certainly applies to any custom port, but in this specific article I will only cover SMTP, which in most cases is port 25.
So I have a mail server running Postfix and and when I connect to port 25 using, say, telnet, it immediately returns this string:
220 customdomain.com ESMTP Postfix (Ubuntu)
When I tell Cloudsome to check every 2 minutes if port 25 is open on this server, I also want to specify exactly what string the response should contain. In my case I will enter “ESMTP Postfix” into the following field:
And this about sums it up. Easy right?