Delivery Alerts

Plivo’s message delivery monitoring systems evaluate the delivery rate of inbound messages every 15 minutes. We calculate delivery rates of all inbound message received for your account in the last hour. An alert is triggered if the percentage of undelivered messages is more than 5%.

For example: 

    At 11:00, we'll evaluate the delivery rate of inbound messages received between 10:00 a.m. and 11:00 a.m.

    If the delivery rate is less than 95%, we'll send an email alert to your configured email address. 

Note: For inbound messages, the validity of an evaluation period is assessed only if at least 10 inbound messages were processed during that one hour. For cases where the number of messages is less than 10 no email alerts are triggered.

This email is triggered when Plivo’s message delivery monitoring systems observe a significant drop in your inbound message delivery rate.

A drop in inbound message delivery rate may be caused by any of the following reasons:

1. An incorrect message URL configured in your Plivo Application
2. An unresponsive message URL
3. The message URL takes more than five seconds to respond to an HTTP request

This email is triggered when Plivo’s message delivery monitoring systems observe a significant drop in your outbound message delivery rate.

The email contains the following information: 

1. Total outbound messages sent in the past hour
2. Total number of undelivered messages in the past hour
3. The number of undelivered messages grouped by Plivo error code

Based on the error code provided, you can take the relevant action to resolve the issue.

You will receive, at most, one email alert per hour (each for inbound and outbound). An email message is triggered only when we observe a significant drop in your inbound or outbound message delivery rate. 

Plivo’s message delivery monitoring systems evaluate the delivery rate of the outbound messages every 15 minutes, and compares it with the delivery rates for the same time period over the last seven days. If we find a 25% or more drop in delivery, we'll send an email alert to the configured email address. 

For example: 

1. At 13:00 Jan 10, 2021, our systems calculated the delivery rate of the messages processed between 12:00 Jan 10, 2021, to 13:00 Jan 10, 2021. Let's assume the delivery rate calculated here is 70%. 
2. This is then compared with average delivery rates over the last seven days (January 4 to 10 ) for the time period 12:00 to 13:00 each day. Say the average delivery rate from these data points is 95%.
3. The drop in delivery rate here is 26.3%, which is more than 25%. This will trigger a delivery degradation email alert to the configured email address.

Note: For outbound messages, an evaluation period is considered valid only if at least 250 outbound messages were processed during that hour. For cases where the number of messages is less than 250, no email alerts are triggered.

Plivo’s systems don't perform health checks on inbound message URLs, but they do monitor inbound message delivery rates. If your inbound message URL is unresponsive, we'll see a drop in inbound message delivery rate. You can enable SMS delivery alerts for your account to receive email whenever we observe a drop in your inbound delivery rates. Enable delivery alerts from the console at Messaging > Alerts.

Go to Messaging > Alerts to configure email alerts for your account. When you enable alerts for your account, Plivo will send you email whenever our delivery rate monitoring systems observe a significant drop in your outbound and/or inbound message delivery rates.

Plivo sends SMS status codes at each stage of the delivery process. Depending on the message_state returned, we may also provide an accompanying error_code. For example, if delivery is unsuccessful when we try to deliver an SMS message to the carrier, the message_state will be updated from “queued” to “failed” and an accompanying error_code will be given.

If a message is successfully sent to the carrier, it can still hit roadblocks that cause it to fail. If the message_state changes from “queued” to “sent” and then to “undelivered,” we'll generate an error_code to help you learn more about a delivery issue. 

This illustration shows a successful delivery path and the message_states that can occur.

See the list of Plivo error codes for outgoing and incoming messages. 

Yes. If the message_url for your Plivo application returns a non-2xx HTTP status code, Plivo will retry the request to the message_url. 

Plivo will make a maximum of three retry attempts:

• The first retry attempt will be made 60 seconds after the original attempt.
• The second retry attempt will be made 120 seconds after the first retry attempt.
• The third retry attempt will be made 240 seconds after the second retry attempt.

Retry attempts are made for both inbound messages and status update callbacks for outbound messages.

Please note that Plivo expects your server to respond to our requests within eight seconds. Requests are timed out if an HTTP response is not received within eight seconds. Timed out requests are retried based on the retry schedule described above. 

For incoming messages, you can set the message_url for your Plivo application using our API or in the Applications tab of the user dashboard. For outgoing messages, you can set the message_url in your API code by adding the parameter "URL" = "https://.example.com/sms".

Outbound messages

Your outbound message could be listed as queued, sent, failed, delivered, or undelivered.

• All outbound messages are initially queued as Plivo accepts the message and attempts to send it to a carrier.
• A message is marked as failed if an internal error occurs before the message is passed on to downstream carriers. Users are not charged for failed messages. 
• A message is marked as sent when the message is successfully passed on to a downstream carrier. Users are charged for sent messages.
• A message is marked delivered or undelivered based on the delivery receipt received from the carrier. Users are charged for these messages.

Note that delivery receipts are not universally supported across countries, number types, or mobile networks. The final status of a message may remain “sent” in cases where delivery receipts are not received. Delivery reports are not supported in the US and Canada due to federal regulations, so it's always good to consider sent + delivered as delivered.

Inbound messages

Your inbound message could be categorized as received, delivered, or undelivered.

• All inbound messages are initially marked as received. 
• If the Plivo phone number that received the message is associated with an application, and the application has a valid message_url configured, then the message will be forwarded to that URL. The message will be marked as delivered following a successful response from the message_url; otherwise, it will be marked as undelivered.