PRTG Manual: SMTP&POP3 Round Trip Sensor
The SMTP&POP3 Round Trip sensor monitors the time it takes for an email to reach a Post Office Protocol version 3 (POP3) mailbox after being sent using the Simple Mail Transfer Protocol (SMTP). It sends an email using the parent device (an SMTP server) and then scans a dedicated POP3 mailbox until the email comes in.
The SMTP&POP3 Round Trip sensor automatically deletes these emails from the mailbox as soon as PRTG has retrieved them. Emails only remain in the mailbox if a timeout or a restart of the PRTG core server occurred during sensor runtime.
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
- Dutch: SMTP & POP3 Round Trip
- French: Durée de boucle SMTP&POP3
- German: SMTP&POP3-Übermittlung
- Japanese: SMTP&POP3 ラウンドトリップ
- Portuguese: Percurso de ida e volta SMTP&POP3
- Russian: Цикл SMTP и POP3
- Simplified Chinese: SMTP 和 POP3 往返
- Spanish: Ida y vuelta SMTP&POP3
- This sensor has a high performance impact. Use it with care. We recommend that you use no more than 200 sensors of this sensor type on each probe.
- The parent device must be an SMTP server.
- This sensor does not support Secure Remote Password (SRP) ciphers.
- Use dedicated email accounts with this sensor. If you use more sensors of this type, make sure that each sensor uses its own email accounts.
The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the setting fields that are required for creating the sensor. Therefore, you do not see all setting fields in this dialog. You can change (nearly) all settings in the sensor's Settings tab later.
Click the Settings tab of a sensor to change its settings.
Usually, a sensor connects to the IP Address or DNS Name of the parent device on which you created the sensor. See the device settings for details. For some sensors, you can explicitly define the monitoring target in the sensor settings. See below for details on available settings.
Setting |
Description |
---|---|
Sensor Name |
Enter a meaningful name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets.
|
Parent Tags |
Shows tags that the sensor inherits from its parent device, parent group, and parent probe. This setting is for your information only. You cannot change it. |
Tags |
Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.
The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:
|
Priority |
Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority ( |
Setting |
Description |
---|---|
From |
Specify the email address of the email's sender. Enter a valid email address. |
To |
Specify the address that PRTG sends the emails to. Enter a valid email address.
|
HELO Ident |
Enter a server name for the HELO part of the mail protocol. For some mail servers, the HELO identifier must be the valid principal host domain name for the client host. For more information, see SMTP RFC 2821. |
Step 1: Send Email Using Parent Device (SMTP Server)
In this step, you configure how PRTG sends the emails. The sensor uses the IP Address/DNS Name of its parent device (an SMTP server).
Setting |
Description |
---|---|
Port |
Enter the number of the port that the sensor uses to send an email via SMTP. The default port for unsecure connections is 25 and the default ports for secure connections are 465 or 587. The actual setting depends on the server you connect to. Enter an integer value. We recommend that you use the default value. If you do not get a connection, try a different port number. |
Timeout for SMTP Connection (Sec.) |
Enter a timeout in seconds for the request. If the reply takes longer than this value, the sensor cancels the request and shows a corresponding error message. Enter an integer value. The maximum value is 900 seconds (15 minutes). |
SMTP Authentication Type |
Define if you want to use authentication for the SMTP connection:
|
Username |
This setting is only visible if you enable Username/password above. Enter a username for SMTP authentication. Enter a string. |
Password |
This setting is only visible if you enable Username/password above. Enter a password for SMTP authentication. Enter a string. |
Additional Text for Email Subject |
PRTG automatically creates the subject part of the round trip email. It consists of the string PRTG Roundtrip Mail:, followed by a unique globally unique identifier (GUID) to correctly identify the email in the POP3 mailbox, for example, PRTG Roundtrip Mail: {5E858D9C-AC70-466A-9B2A-55630165D276}. Use this field to place your custom text before the automatically created text. |
Setting |
Description |
---|---|
SMTP Specific |
Define the security of the connection:
|
Step 2: Check a POP3 Mailbox until Email Arrives
In this step, you configure how to receive the sent emails.
Setting |
Description |
---|---|
IP Address/DNS Name |
Specify the POP3 server. Enter a valid IP address or Domain Name System (DNS) name. |
Port |
Specify the port that the sensor uses for the POP3 connection. The default port for unsecure connections is 143 and the default port for secure connections is 993. The actual setting depends on the server you are connecting to. Enter an integer value. We recommend that you use the default value. If you do not get a connection, try a different port number. |
Connection Interval (Sec.) |
Enter the number of seconds the sensor waits between two connections to the POP3 server. PRTG continuously checks the mailbox in this scanning interval until the email arrives. Enter an integer value. |
Maximum Trip Time (Sec.) |
Enter the number of seconds an email may take to arrive in the POP3 mailbox. PRTG continuously checks the mailbox in the interval that you specify above until the email arrives. If it does not arrive within the maximum trip time, the sensor triggers an error message. Enter an integer value. |
POP3 Authentication Type |
Select the kind of authentication for the POP3 connection:
|
Username |
This setting is only visible if you enable an option with login above. Enter a username for POP3 authentication. Enter a string. |
Password |
This setting is only visible if you enable an option with login above. Enter a username for POP3 authentication. Enter a string. |
Setting |
Description |
---|---|
POP3 Specific |
Define the security of the connection:
|
Setting |
Description |
---|---|
Result Handling |
Define what PRTG does with the sensor result:
|
Setting |
Description |
---|---|
Primary Channel |
Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.
|
Graph Type |
Define how different channels are shown for this sensor:
|
Stack Unit |
This setting is only visible if you enable Stack channels on top of each other as Graph Type. Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so. |
By default, all of the following settings are inherited from objects that are higher in the hierarchy. You should change them centrally in the root group settings if necessary. To change a setting for this object only, click under the corresponding setting name to disable the inheritance. You then see the options described below.
For more information, see section Inheritance of Settings.
Click to interrupt the inheritance.
Setting |
Description |
---|---|
Scanning Interval |
Select a scanning interval from the dropdown list. The scanning interval determines the amount of time that the sensor waits between two scans. Choose from:
|
If a Sensor Query Fails |
Select the number of scanning intervals that the sensor has time to reach and to check a device again if a sensor query fails. Depending on the option that you select, the sensor can try to reach and to check a device again several times before the sensor shows the Down status. This can avoid false alarms if the monitored device only has temporary issues. For previous scanning intervals with failed requests, the sensor shows the Warning status. Choose from:
|
Schedules, Dependencies, and Maintenance Windows
You cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.
Setting |
Description |
---|---|
Schedule |
Select a schedule from the list. You can use schedules to monitor during a certain time span (days or hours) every week. Choose from:
|
Maintenance Window |
Select if you want to set up a one-time maintenance window. During a maintenance window, monitoring stops for the selected object and all child objects. They show the Paused status instead. Choose between:
|
Maintenance Begins |
This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the start date and time of the one-time maintenance window. |
Maintenance Ends |
This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the end date and time of the one-time maintenance window. |
Dependency Type |
Select a dependency type. You can use dependencies to pause monitoring for an object depending on the status of a different object. You can choose from:
|
Dependency |
This setting is only visible if you enable Select a sensor above. Click |
Dependency Delay (Sec.) |
This setting is only visible if you enable Select a sensor above. Define a time span in seconds for the dependency delay. After the master sensor for this dependency returns to the Up status, PRTG additionally delays the monitoring of the dependent objects by the time span you define. This can prevent false alarms, for example, after a server restart or to give systems more time for all services to start. Enter an integer value.
|
Click to interrupt the inheritance.
Setting |
Description |
---|---|
User Group Access |
Define the user groups that have access to the sensor. You see a table with user groups and group access rights. The table contains all user groups in your setup. For each user group, you can choose from the following group access rights:
|
Which channels the sensor actually shows might depend on the monitored device, the available components, and the sensor setup.
Channel |
Description |
---|---|
Downtime |
In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status in percent. |
Response Time (POP3) |
The response time of the POP3 server in milliseconds (msec) |
Response Time (SMTP) |
The response time of the SMTP server in msec |
Total |
The sum of the response time of the SMTP server and the POP3 server in msec
|
KNOWLEDGE BASE
What security features does PRTG include?
For more information about sensor settings, see the following sections: