Receiving the same notification multiple times
This situation often occurs from misconfigured 3rd party software that sends messages through our API.
Emergency-priority Messages
Each message sent to Pushover's API can include a user-specified priority which alters how the message is handled. (Contrary to the documentation of some 3rd party software, this priority has no affect on how quickly your message is processed or delivered through Pushover.) The highest priority, emergency (2), will repeat the alert multiple times until you acknowledge it by tapping on the notification and then tapping on the "Acknowledge" button in the app. These emergency-priority messages are indicated by a bright red background in the message list, and the label "Emergency priority" under the title in the dedicated message view.
If you are receiving repeating emergency-priority messages and you do not want this repeating behavior, change the message priority in the software you use to generate Pushover notifications to use the default (0) or just high-priority (1) which will not repeat.
Duplicate Instances
For server-side software such as network monitors or cron tasks that send Pushover notifications, it may be possible that the software is running twice and sending two messages to our API each time.
If the same message appears multiple times in the message list of the Pushover app, then our API is receiving multiple messages from your software. Verify that it is not running twice on your servers (or however the messages are generated).
Multiple E-mails
For messages received through our e-mail gateway, the same situation can occur where multiple e-mails are received by our servers and converted to notifications. Verify on the sending side that multiple e-mails are not being sent out.