Using the SMTP/SMTPS monitor in Anturis Console, you can set up monitoring of general availability and response time for any remote email server connected to the internet (such as a Microsoft Exchange server). It also enables you to set up a notification when a certificate for a secure TLS/SSL connection is about to expire. You can send requests either from one of the components in your infrastructure, or use one of the available Public Agents that are maintained by Anturis in different geographical locations.
Simple Mail Transfer Protocol (SMTP) is used by email servers for sending messages to other email servers, and by email clients for sending messages to email servers. To retrieve messages from servers, email clients use either the Post Office Protocol (POP) or the Intenet Message Access Protocol (IMAP). This is why email clients require you to specify both an incoming and an outgoing email server. SMTP is a delivery protocol, designed to push email messages to a target server.
The default port number that an SMTP server listens on is either 25 or 587 (for mail submission). The server requires a username and password to authenticate a client. However, SMTP does not encrypt messages, so your credentials may be read by a third party involved in the connection. To provide an encrypted connection, SMTP can be used over the Transport Layer Security (TLS) protocol, which was previously known as Secure Socket Layer (SSL). When SMTP is used over a TLS/SSL layer this is called an SMTPS connection, and it is directed through port 465 by default. As an alternative you can establish a TLS/SSL connection over the standard SMTP submission interface on port 587 using the STARTTLS extension.
TLS/SSL are cryptographic protocols for secure communication over computer networks. They are based on the exchange of X.509 certificates and public keys for encrypting and decrypting messages. Digital certificates are issued by a certificate authority (CA) trusted by both parties involved in the communication. A certificate binds the public key to a person or organization for a predetermined period of time (until the certificate expires).
By regularly sending SMTP requests and tracking the time it takes for a response to be returned (also known as round-trip delay time, latency, or timeout), you can ensure the availability and performance of your critical email servers. This directly affects the quality of your service, because your clients or employees rely on email every day. The sooner you are able to detect a possible issue, the faster you will be able to react to it. If the server uses TLS/SSL security, it is also important to monitor the certificate expiration date.