RBL Monitoring

What better way to top off our email monitoring enhancements than with a new check type! We’re happy to introduce our RBL check.

RBL, or DNSBL, stands for “Real-time Black List,” and is used to publish the addresses of computers or networks linked to spamming, malware, or other abuses which system administrators may want to block from accessing their networks.

There are hundreds of RBLs in existence, which use a wide array of criteria for listing and delisting of addresses. These may include listing the addresses of zombie computers or other machines being used to send spam, listing the addresses of ISPs who willingly host spammers, or listing addresses which have sent spam to a honeypot system.

If the IP addresses of your servers appear on these RBLs, there’s a good chance you’ll have difficulty interacting with networks that subscribe to these RBLs. For instance, if your SMTP server is listed, you’ll likely be unable to send email to the systems that use the RBL you are listed on.

You can use our new RBL check to ensure that your servers aren’t listed and to receive notifications if they do get listed, allowing you to quickly take steps to remove your addresses from those RBLs. You can find more details about which RBLs we check and how to set them up in our RBL Check documentation.

Adding RBL checking to our already robust email monitoring checks for SMTP, POP3, and IMAP4 will help you sleep at night knowing that email is flowing as it should be.

RBL monitoring checks are available to all NodePing accounts. If you don’t have an account yet, you can sign up for your free 15-day trial of our server monitoring service.

SMTP Check Enhancements

We’ve rolled out some important enhancements to our SMTP check that will help ensure your email server is running as it should be.

Added enhancements include:

  • Non-standard ports
  • SSL/TLS support including certificate verification and expiration warning
  • STARTTLS support
  • AUTH with support for PLAIN, LOGIN, and CRAM-MD5
  • Mail acceptance verification including open relay notification

The SMTP check will now not only verify that your email server is running but can also optionally check to see if your server is an open relay or properly accepting mail for a particular email address.

The new open relay functionality will test to see if your mail server will accept mail for an address that should not be allowed. If your server is an open relay, we will send you a notification.

It’s also important to verify that your email server is not rejecting mail that it should be accepting. There are many reasons an SMTP server may reject email. The configuration may have changed or a particular mailbox may be over its quota. This enhancement verifies that your server will accept messages to an email address of your choice and send you a notification if it is rejected.

We’ve added extensive SSL/TLS support including STARTTLS as well as certificate verification and certificate expiration warnings. Simply set how many days in advance of the expiration you would like to be notified and we’ll send you an alert, giving you time to renew and install your new certificates.

The new optional AUTH support allows you to verify that users can log in and send mail using industry standard PLAIN, LOGIN, and CRAM-MD5 AUTH mechanisms.

You can find more information about our new SMTP check enhancements in our documentation.

These enhancements are available now to all NodePing customers. If you don’t currently have an account, please sign up for our free 15 day trial.