PRTG Manual: System Administration—Notification Delivery

SMTP Delivery Mechanism

Define how PRTG sends emails using Simple Mail Transfer Protocol (SMTP). Choose between:

• Direct delivery using built-in email relay server (default): Use the SMTP relay server built into PRTG. This server manages its own email queue. For each email, it looks up the target SMTP server via the MX record of the target domain, and send the email.
• Use SMTP relay server (recommended inside LANs/NATs): Set up your own SMTP relay server to send emails. Enter data below.
• Use two SMTP relay servers (primary and fallback server): Set up two own SMTP relay servers—one primary and one as fallback server. Enter data below.

When monitoring inside your NAT or LAN, it is often a good idea to use your own LAN-based relay server to deliver notification emails quicker.

Sender Email

Enter an email address to use as sender of all emails. This setting is global and can only be changed centrally here.

Sender Name

Enter a name to use as sender of all emails. This setting is global and can only be changed centrally here.

HELO Ident

Enter the HELO Ident for SMTP. This must be a unique name, preferably the DNS name of the machine running PRTG. See SMTP RFC 2821: The sender-SMTP must ensure that the domain parameter in a HELO command is a valid principal host domain name for the client host.

SMTP Relay Server

This field is only visible if you enable SMTP relay server above. Enter the IP address or DNS name of the SMTP relay server.

SMTP Relay SMTP Port

This field is only visible if you enable SMTP relay server above. Enter the port number the SMTP relay server is running on. Standard value is 25.

SMTP Relay Authentication

This field is only visible if you enable SMTP relay server above. Select the kind of authentication required for the SMTP server. Choose between:

• No authentication is required: Use SMTP without authentication.
• Use standard SMTP authentication: Use standard authentication.
• SASL authentication is required: Use secure authentication via Simple Authentication and Security Layer (SASL).

SMTP Relay User

This field is only visible if you enable SMTP authentication above. Enter a valid username.

SMTP Relay Password

This field is only visible if you enable SMTP authentication above. Enter a valid password.

Use Encrypted Connection

This field is only visible if you enable SMTP relay server above. Enter the security level for SMTP connections. Choose between:

• Never: Use insecure connection with plain text transfer.
• If supported by server: Use a secure connection (default).

SSL Method

This setting is only visible if you enable SMTP relay server and encryption above. It is only relevant for secure connections. Select the SSL or TLS version that your SMTP device supports.

We recommend that you use the default value. If you do not get a connection, try with another setting. Choose between:

• SSL V2
• SSL V2 or V3
• SSL V3
• TLS V1
• TLS V1.1
• TLS V1.2

SMTP Relay Server (Fallback)

These fields are only visible if you enable the option for two SMTP relay servers above. Please see also the settings that you made for your primary SMTP relay server.

SMTP Relay SMTP Port (Fallback)

SMTP Relay Authentication (Fallback)

Use Encrypted Connection (Fallback)

SSL Method (Fallback)

SMTP Relay User (Fallback)

SSL Method (Fallback)

SMTP Relay User (Fallback)

SMTP Relay Password (Fallback)

Security (Fallback)

Although PRTG has built-in support for the Application Programming Interface (API) of some SMS providers, we cannot officially provide support regarding these SMS service providers. If you have technical questions about SMS delivery beyond PRTG, please contact your SMS provider directly.

Instead of using a pre-configured provider you can always use a custom URL, enabling you to use extended parameters (this is also an alternative when using providers for which we offer pre-configured options).

You need an internet connection to send text messages via the HTTP API.

For information about sending SMS via separate hardware using third-party software, see this Knowledge Base article: How can I send SMS text message notifications via a modem or a mobile phone with PRTG?

Configuration Mode

Define how you want to select an SMS provider. Choose between:

• Select an SMS provider from a list of providers: Select a provider from a list below.
• Enter a custom URL for a provider not listed: Use another provider and enter the service URL manually below.

Service Provider

This field is only visible if you choose the provider list above. Select a service provider from the list. PRTG offers a small incomplete list of providers.

Some providers might require a port configuration in your firewall. For details, see this Knowledge Base article: Which URLs does PRTG use for its preconfigured SMS providers?

User

This field is only visible if you choose the provider list above. Enter a username for the service provider account.

Password

This field is only visible if you choose the provider list above. Enter a password for the service provider account.

API ID / Account

This field is only visible if you choose the provider list above. Some providers need an additional API ID or account information. If provided, enter it here. Please enter a string or leave the field empty.

Custom URL

This field is only visible if you enable the custom provider option above. From the documentation of your SMS provider, enter the service URL that is used to send SMS messages.

Use the following placeholders for the recipient phone number and the text message:

• %SMSNUMBER
• %SMSTEXT

Please use the GET method to request the custom URL. POST requests are not supported.

Custom URL-SNI

Select if PRTG will send the SNI extension to the TLS protocol along with the HTTP request. Choose between:

• Do not send SNI (default): PRTG will not send an SNI when executing the HTTP action.
• Send SNI: PRTG will send an SNI when calling the target URL. Specify the SNI below.

Virtual Host (SNI)

This field is only visible if you select the SNI option above. Enter the SNI name that your endpoint configuration requires. Usually, this is the Fully Qualified Domain Name (FQDN) of the virtual host.

Encoding for SMS

Define the encoding of the URL string that PRTG sends to your provider. Choose between:

• ANSI local system codepage (default)
• UTF-8
• UTF-16

Maximum Length of Text

Some SMS providers will not allow SMS messages exceeding a certain amount of characters. PRTG will restrict the number of characters according to the length specified in this field. A value of 0 means the SMS is sent at its full length.