Connectivity issue on smpp3.nexmo.com and smpp4.nexmo.com

The delivery receipts functionality on SMPP3 / SMPP4 has been restored. Customers should be able to receive DLRs correctly.

We are seeing problems on SMPP3 / SMPP4 impacting missing Delivery Receipts.

Our Engineering team is investigating, and we will update this post as soon as more information is available.

We have implemented a fix for this issue and will continue monitoring the results.

This incident started at 04:55 UTC, and was resolved at 5:59 UTC.

If your company restricts network traffic, such as IP based filtering, please update your firewall allow-list with the following IPs:

smpp3.nexmo.com -> 172.65.228.126
smpp4.nexmo.com -> 172.65.198.19

We apologise for any inconvenience this may cause. Please contact support@api.vonage.com if you need any further assistance.

Our monitoring has alerted us to a potential service issue with connectivity binding to our SMPP servers: smpp3.nexmo.com / smpp4.nexmo.com

We are alerting customers immediately while our engineering teams investigate.

Please see this article - https://help.nexmo.com/hc/en-us/articles/360015693092-Nexmo-Incident-Handling - for an explanation of our approach to publishing incidents.