---
title: "Simple & Easy Notification Service troubleshooting"
slug: "sens-troubleshoot"
updated: 2026-10-08T06:42:00Z
published: 2026-10-08T06:42:00Z
canonical: "guide.ncloud-docs.com/sens-troubleshoot"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://guide.ncloud-docs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Simple & Easy Notification Service troubleshooting

Available in Classic and VPC

Learn how to resolve issues with Simple & Easy Notification Service. Click any error for detailed troubleshooting steps.

## Troubleshoot common issues

The following are examples of common errors you might encounter:

[Project creation limit](/docs/en/sens-troubleshoot-common#%ED%94%84%EB%A1%9C%EC%A0%9D%ED%8A%B8%EC%83%9D%EC%84%B1%ED%95%9C%EB%8F%84%EC%A0%9C%ED%95%9C) I didn't create any projects, but the creation limit notification appears.

[Unable to view the delivery history](/docs/en/sens-troubleshoot-common#%EB%B0%9C%EC%86%A1%EB%82%B4%EC%97%AD%ED%99%95%EC%9D%B8%EB%B6%88%EA%B0%80) I can't view the history of messages sent 2 months ago.

## Troubleshoot Biz Message issues

The following are examples of Biz Message-related issues you might encounter:

[KakaoTalk Channel registration errors](/docs/en/sens-troubleshoot-bizmessage#%EC%B9%B4%EC%B9%B4%EC%98%A4%ED%86%A1%EC%B1%84%EB%84%90%EB%93%B1%EB%A1%9D%EC%98%A4%EB%A5%98) KakaoTalk Channel is not registered in the console. I received the message "The channel and template features you requested cannot be processed. Check the status and try again." I received the message "Check the KakaoTalk Channel status."

[Enter Customer Center information](/docs/en/sens-troubleshoot-bizmessage#%EA%B3%A0%EA%B0%9D%EC%84%BC%ED%84%B0%EC%A0%95%EB%B3%B4%EC%9E%85%EB%A0%A5) When creating a channel, I received the message "Entry of customer center information is required for the outgoing profile channel to be registered." I received the message "The requested channel operation cannot be performed." Cannot locate the field for entering customer center information.

[Unable to register channels](/docs/en/sens-troubleshoot-bizmessage#%EC%B1%84%EB%84%90%EB%93%B1%EB%A1%9D%EB%B6%88%EA%B0%80) Channel cannot be registered. I received the message that registration is not possible due to a history of channel deletion.

[Channel deletion delay](/docs/en/sens-troubleshoot-bizmessage#%EC%B1%84%EB%84%90%EC%82%AD%EC%A0%9C%EC%A7%80%EC%97%B0) Channel deletion is delayed. The channel I deleted and tried to register again still remains in "Deleting" status.

[AlimTalk reception failed](/docs/en/sens-troubleshoot-bizmessage#%EC%95%8C%EB%A6%BC%ED%86%A1%EC%88%98%EC%8B%A0%EC%8B%A4%ED%8C%A8) AlimTalk delivery request was successful, but the reception status is displayed as failed. The API response shows the status as "COMPLETED", but the notification was not delivered.

[Change channels connected to templates](/docs/en/sens-troubleshoot-bizmessage#%ED%85%9C%ED%94%8C%EB%A6%BF%EC%97%90%EC%97%B0%EA%B2%B0%EB%90%9C%EC%B1%84%EB%84%90%EB%B3%80%EA%B2%BD) The wrong channel was selected for template approval. I am operating multiple channels and want to change the channel connected to an approved template.

[Redirected to the project page when registering AlimTalk templates](/docs/en/sens-troubleshoot-bizmessage#%EC%95%8C%EB%A6%BC%ED%86%A1%ED%85%9C%ED%94%8C%EB%A6%BF%EB%93%B1%EB%A1%9D%EC%8B%9C%ED%94%84%EB%A1%9C%EC%A0%9D%ED%8A%B8%ED%8E%98%EC%9D%B4%EC%A7%80%EB%A1%9C%EC%9D%B4%EB%8F%99) I am redirected to the project page when registering an AlimTalk template.

[Template approval delay](/docs/en/sens-troubleshoot-bizmessage#%ED%85%9C%ED%94%8C%EB%A6%BF%EC%8A%B9%EC%9D%B8%EC%A7%80%EC%97%B0) The AlimTalk template inspection request is still in progress. Template approval is not being completed.

[Error message: "Template button format is not valid"](/docs/en/sens-troubleshoot-bizmessage#%ED%85%9C%ED%94%8C%EB%A6%BF%EB%B2%84%ED%8A%BC%ED%98%95%EC%8B%9D%EC%9D%B4%EC%9C%A0%ED%9A%A8%ED%95%98%EC%A7%80%EC%95%8A%EC%9D%8C%EC%98%A4%EB%A5%98%EB%A9%94%EC%8B%9C%EC%A7%80) I received the message "Template button format is not valid." An error occurs even when applying the same settings as a previously registered template.

[Unable to preview messages](/docs/en/sens-troubleshoot-bizmessage#%EB%A9%94%EC%8B%9C%EC%A7%80%EB%AF%B8%EB%A6%AC%EB%B3%B4%EA%B8%B0%EB%B6%88%EA%B0%80) Message previews are unavailable upon receipt, even though the template is not registered as a security template.

[Errors when entering Korean in the channel name](/docs/en/sens-troubleshoot-bizmessage#%EC%B1%84%EB%84%90%EB%AA%85%EC%97%90%ED%95%9C%EA%B8%80%EC%9E%85%EB%A0%A5%EC%8B%9C%EC%98%A4%EB%A5%98) When the channel name is entered in Korean in API parameters, a 401 unauthorized error occurs.

[Unable to edit or delete AlimTalk](/docs/en/sens-troubleshoot-bizmessage#%EC%95%8C%EB%A6%BC%ED%86%A1%EC%88%98%EC%A0%95%EB%B0%8F%EC%82%AD%EC%A0%9C%EB%B6%88%EA%B0%80) The button to edit or delete a registered AlimTalk message is disabled.

[Error 3016 and error message: "Message content does not match the template"](/docs/en/sens-troubleshoot-bizmessage#3016%EC%98%A4%EB%A5%98%EC%BD%94%EB%93%9C%EB%A9%94%EC%8B%9C%EC%A7%80%EB%82%B4%EC%9A%A9%EC%9D%B4%ED%85%9C%ED%94%8C%EB%A6%BF%EA%B3%BC%EC%9D%BC%EC%B9%98%ED%95%98%EC%A7%80%EC%95%8A%EC%9D%8C%EC%98%A4%EB%A5%98%EB%A9%94%EC%8B%9C%EC%A7%80) I received error code 3016. I received the message "Message content does not match the template." The request succeeded, but the reception is displayed as failed.

[Error 3018 and error message: "Message could not be sent"](/docs/en/sens-troubleshoot-bizmessage#3018%EC%98%A4%EB%A5%98%EC%BD%94%EB%93%9C%EB%A9%94%EC%8B%9C%EC%A7%80%EB%A5%BC%EC%A0%84%EC%86%A1%ED%95%A0%EC%88%98%EC%97%86%EC%9D%8C%EC%98%A4%EB%A5%98%EB%A9%94%EC%8B%9C%EC%A7%80) I received error code 3018. I received the message "Message could not be sent."

## Troubleshoot SMS issues

The following are examples of SMS related errors you might encounter:

[reserveTime setting errors](/docs/en/sens-troubleshoot-sms#reserveTime%EC%84%A4%EC%A0%95%EC%98%A4%EB%A5%98) When the scheduled message's reserveTime extends beyond approximately 6 months from now, an error occurs.

[Unable to unsubscribe from 080 Block Call Service](/docs/en/sens-troubleshoot-sms#080BlockCallService%ED%95%B4%EC%A7%80%EB%B6%88%EA%B0%80) I can't unsubscribe from 080 Block Call Service.

[Sending limit increase](/docs/en/sens-troubleshoot-sms#%EB%B0%9C%EC%86%A1%ED%95%9C%EB%8F%84%EC%83%81%ED%96%A5) The sending limit is too low. I want to increase the sending limit for domestic and international SMS (including LMS and MMS).

[Error 3009](/docs/en/sens-troubleshoot-sms#3009%EC%98%A4%EB%A5%98%EC%BD%94%EB%93%9C) When I sent an MMS, I received Error 3009.

[Error 3014 and error message: "Other"](/docs/en/sens-troubleshoot-sms#3014%EC%98%A4%EB%A5%98%EC%BD%94%EB%93%9C%EA%B8%B0%ED%83%80%EC%98%A4%EB%A5%98%EB%A9%94%EC%8B%9C%EC%A7%80) I received error code 3014. I received Error 3014, but only the message "Other" is displayed.

[Error 3015 and error message: "No delivery path"](/docs/en/sens-troubleshoot-sms#3015%EC%98%A4%EB%A5%98%EC%BD%94%EB%93%9C%EC%A0%84%EC%86%A1%EA%B2%BD%EB%A1%9C%EC%97%86%EC%9D%8C%EC%98%A4%EB%A5%98%EB%A9%94%EC%8B%9C%EC%A7%80) I received error code 3015. I received the error message "No delivery path."

[Error 3018](/docs/en/sens-troubleshoot-sms#3018%EC%98%A4%EB%A5%98%EC%BD%94%EB%93%9C) I sent an SMS message and received Error 3018.

[Replacement of specific characters with special characters in messages](/docs/en/sens-troubleshoot-sms#%EB%A9%94%EC%8B%9C%EC%A7%80%EC%97%90%EC%84%9C%ED%8A%B9%EC%A0%95%EB%AC%B8%EC%9E%90%EA%B0%80%ED%8A%B9%EC%88%98%EB%AC%B8%EC%9E%90%EB%A1%9C%EC%B9%98%ED%99%98) When I send an SMS message, specific characters are replaced with the character "?".

[Change the registered calling number](/docs/en/sens-troubleshoot-sms#%EB%93%B1%EB%A1%9D%EB%90%9C%EB%B0%9C%EC%8B%A0%EB%B2%88%ED%98%B8%EB%B3%80%EA%B2%BD) I want to change the registered calling number.

## Troubleshoot MAIL issues

[Image errors in email attachments](/docs/en/sens-troubleshoot-mail#%EB%A9%94%EC%9D%BC%EC%97%90%EC%B2%A8%EB%B6%80%EB%90%9C%EC%9D%B4%EB%AF%B8%EC%A7%80%EC%98%A4%EB%A5%98) Images attached to Cloud Outbound Mailer emails are not displayed.

[Mail delivery failure to Gmail recipients](/docs/en/sens-troubleshoot-mail#Gmail%EC%88%98%EC%8B%A0%EC%9E%90%EC%97%90%EA%B2%8C%EB%A9%94%EC%9D%BC%EB%B0%9C%EC%86%A1%EC%8B%A4%ED%8C%A8) Sending mail to Gmail recipients fails.

[Unable to view mail delivery logs](/docs/en/sens-troubleshoot-mail#%EB%A9%94%EC%9D%BC%EB%B0%9C%EC%86%A1%EB%A1%9C%EA%B7%B8%ED%99%95%EC%9D%B8%EB%B6%88%EA%B0%80) There are no logs for the mail I sent.

["NONEXISTENT_DOMAIN_ADDRESS" delivery result code and "Recipient domain does not exist" delivery result message](/docs/en/sens-troubleshoot-mail#NONEXISTENTDOMAINADDRESS%EC%98%A4%EB%A5%98%EB%A9%94%EC%8B%9C%EC%A7%80) When I send mail, the delivery result code is "NONEXISTENT_DOMAIN_ADDRESS", and the delivery result message is "Recipient domain does not exist".

[Error message: "Connection reset"](/docs/en/sens-troubleshoot-mail#Connectionreset%EC%98%A4%EB%A5%98%EB%A9%94%EC%8B%9C%EC%A7%80) I received the error message "Connection reset".

[Bulk mail delivery failure](/docs/en/sens-troubleshoot-mail#%EB%8C%80%EB%9F%89%EB%A9%94%EC%9D%BC%EB%B0%9C%EC%86%A1%EB%B0%9C%EC%86%A1%EC%8B%A4%ED%8C%A8) Many messages fail when sending bulk mail.

[Unable to view or remove send block list entries in bulk](/docs/en/sens-troubleshoot-mail#%EB%B0%9C%EC%86%A1%EC%B0%A8%EB%8B%A8%EB%AA%A9%EB%A1%9D%EC%9D%BC%EA%B4%84%EC%A1%B0%ED%9A%8C%ED%95%B4%EC%A0%9C%EB%B6%88%EA%B0%80) I want to view or remove all addresses registered in the Send block list at once.

[Delivery failed but received status displayed as Y](/docs/en/sens-troubleshoot-mail#%EB%B0%9C%EC%86%A1%EC%8B%A4%ED%8C%A8%EC%9D%B8%EB%8D%B0%EC%88%98%EC%8B%A0%EC%97%AC%EB%B6%80%EA%B0%80Y%EB%A1%9C%ED%91%9C%EC%8B%9C) The mail delivery result is failed, but the received status is displayed as Y.

[Received status not updated](/docs/en/sens-troubleshoot-mail#%EC%88%98%EC%8B%A0%EC%97%AC%EB%B6%80%EA%B0%80%EA%B0%80%EB%B0%98%EC%98%81%EB%90%98%EC%A7%80%EC%95%8A%EC%9D%8C) I received the mail, but the received status is not updated.

[Mail delivery failure through API](/docs/en/sens-troubleshoot-mail#API%EB%A5%BC%ED%86%B5%ED%95%9C%EB%A9%94%EC%9D%BC%EB%B0%9C%EC%86%A1%EC%8B%A4%ED%8C%A8) I tried to send mail through the Cloud Outbound Mailer API, but the "IP not allowed for authentication." error occurred.

[Delivery delay when sending bulk mail](/docs/en/sens-troubleshoot-mail#%EB%8C%80%EB%9F%89%EB%A9%94%EC%9D%BC%EB%B0%9C%EC%86%A1%EC%8B%9C%EC%88%98%EC%8B%A0%EC%A7%80%EC%97%B0) I sent bulk mail, but it takes a long time to be received.

[Delivery failure displayed](/docs/en/sens-troubleshoot-mail#%EB%B0%9C%EC%86%A1%EC%8B%A4%ED%8C%A8%ED%91%9C%EC%8B%9C) The mail delivery result is displayed as "Delivery failed".

[DKIM authentication failure](/docs/en/sens-troubleshoot-mail#DKIM%EC%9D%B8%EC%A6%9D%EC%8B%A4%ED%8C%A8) DKIM authentication fails.

[DKIM authentication failure despite signature value retrieval](/docs/en/sens-troubleshoot-mail#DKIM%EC%84%9C%EB%AA%85%EA%B0%92%EC%9D%B4%EC%A1%B0%ED%9A%8C%EB%90%98%EB%82%98%EC%9D%B8%EC%A6%9D%EC%8B%A4%ED%8C%A8) The DKIM signature value is successfully retrieved, but DKIM authentication fails.

[Mail delivery failure after DKIM authentication is complete](/docs/en/sens-troubleshoot-mail#DKIM%EC%9D%B8%EC%A6%9D%EC%99%84%EB%A3%8C%EC%83%81%ED%83%9C%EC%97%90%EC%84%9C%EB%A9%94%EC%9D%BC%EB%B0%9C%EC%86%A1%EC%8B%A4%ED%8C%A8) I completed DKIM authentication, but delivery results alternate between success and failure when sending mail.

[Domain records can be retrieved but authentication fails](/docs/en/sens-troubleshoot-mail#%EB%8F%84%EB%A9%94%EC%9D%B8%EB%A0%88%EC%BD%94%EB%93%9C%EC%A1%B0%ED%9A%8C%EA%B0%80%EB%8A%A5%ED%95%98%EB%82%98%EC%9D%B8%EC%A6%9D%EC%8B%A4%ED%8C%A8) The domain records are registered properly and can be retrieved, but authentication fails.

[Records registered properly but authentication fails](/docs/en/sens-troubleshoot-mail#%EB%A0%88%EC%BD%94%EB%93%9C%EA%B0%80%EC%A0%95%EC%83%81%EB%93%B1%EB%A1%9D%EB%90%98%EC%97%88%EC%9C%BC%EB%82%98%EC%9D%B8%EC%A6%9D%EC%8B%A4%ED%8C%A8) Authentication fails even though the SPF or DKIM records are registered properly.

[SPF authentication failure](/docs/en/sens-troubleshoot-mail#SPF%EC%9D%B8%EC%A6%9D%EC%8B%A4%ED%8C%A8) SPF authentication fails.

## Learning resources

We offer various materials for you to explore. To learn more about Simple & Easy Notification Service, check out these helpful links:

- FAQs: [Simple & Easy Notification Service FAQs](https://www.ncloud.com/support/faq/prod?categoryCode2=APP&categoryCode3=SV_0065&page=1)
- [Simple & Easy Notification Service API guide](https://api.ncloud-docs.com/docs/en/sens-overview)
- NAVER Cloud Platform blog:
  - [Sending SMS with Simple & Easy Notification Service (SENS), Ncloud's bulk text messaging service](https://blog.naver.com/n_cloudplatform/223036731036)
  - [More powerful personalized mail delivery service, Cloud Outbound Mailer](https://blog.naver.com/n_cloudplatform/222135949881?trackingCode=blog_bloghome_searchlist) *(before service integration)*
- [Simple & Easy Notification Service #2: Kafka usage experience for message delivery](https://blog.naver.com/n_cloudplatform/222602219000)

Note

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