# Kernel notifier couldn't install **URL:** \ **Category:** General\ **Created:** [September 7, 2023, 6:35am UTC](https://community.mosip.io/t/kernel-notifier-couldnt-install/753 "2023-09-07T06:35:15Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![mengleang-ngoun](https://dub1.discourse-cdn.com/flex017/user_avatar/community.mosip.io/mengleang-ngoun/32/568_2.png) [@mengleang-ngoun](https://community.mosip.io/u/mengleang-ngoun)\ **Post date:** [September 7, 2023, 6:35am UTC](https://community.mosip.io/t/kernel-notifier-couldnt-install/753/1 "2023-09-07T06:35:15Z")
Hello MOSIP team, we install MOSIP kernel module but we have this problem Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder ‘smtp.host’ in value “${smtp.host}” Thu, Sep 7 2023 1:32:46 pm at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:172) Thu, Sep 7 2023 1:32:46 pm at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) Thu, Sep 7 2023 1:32:46 pm at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:237) Thu, Sep 7 2023 1:32:46 pm at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:211) Thu, Sep 7 2023 1:32:46 pm at org.springframework.core.env.AbstractPropertyResolver.resolveNestedPlaceholders(AbstractPropertyResolver.java:228) Thu, Sep 7 2023 1:32:46 pm at org.springframework.core.env.PropertySourcesPropertyResolver.getProperty(PropertySourcesPropertyResolver.java:88) Thu, Sep 7 2023 1:32:46 pm at org.springframework.core.env.PropertySourcesPropertyResolver.getProperty(PropertySourcesPropertyResolver.java:62) Thu, Sep 7 2023 1:32:46 pm at org.springframework.core.env.AbstractEnvironment.getProperty(AbstractEnvironment.java:531) Thu, Sep 7 2023 1:32:46 pm at org.springframework.boot.autoconfigure.condition.OnPropertyCondition$Spec.collectProperties(OnPropertyCondition.java:150) Thu, Sep 7 2023 1:32:46 pm at org.springframework.boot.autoconfigure.condition.OnPropertyCondition$Spec.access$000(OnPropertyCondition.java:114) Thu, Sep 7 2023 1:32:46 pm at org.springframework.boot.autoconfigure.condition.OnPropertyCondition.determineOutcome(OnPropertyCondition.java:96) Thu, Sep 7 2023 1:32:46 pm at org.springframework.boot.autoconfigure.condition.OnPropertyCondition.getMatchOutcome(OnPropertyCondition.java:58) ---
**Author:** ![Rakshitha](https://avatars.discourse-cdn.com/v4/letter/r/f0a364/32.png) [@Rakshitha](https://community.mosip.io/u/Rakshitha)\ **Post date:** [September 11, 2023, 9:04am UTC](https://community.mosip.io/t/kernel-notifier-couldnt-install/753/2 "2023-09-11T09:04:43Z")
“The error you’re encountering, which suggests an issue with resolving the ‘smtp.host’ placeholder in the configuration, can be resolved by ensuring that the SMTP service is installed, verifying that the ‘kernel-default.properties’ file is up to date, and confirming that it has been successfully passed through the ConfigServer. Additionally, please make sure that the ‘smtp.host’ placeholder is defined and correctly configured in your configuration files, and that the value for ‘smtp.host’ is provided and up to date.” ---
**Author:** ![mengleang-ngoun](https://dub1.discourse-cdn.com/flex017/user_avatar/community.mosip.io/mengleang-ngoun/32/568_2.png) [@mengleang-ngoun](https://community.mosip.io/u/mengleang-ngoun)\ **Post date:** [September 12, 2023, 6:29am UTC](https://community.mosip.io/t/kernel-notifier-couldnt-install/753/3 "2023-09-12T06:29:20Z")
Thank you, So we have to define **${email.smtp.host}, ${email.smtp.username}, ${email.smtp.secret}, ${email.smtp.port}** directly in kernel-default.properties or we have another way to passing it from env or config map. **Note: we use mock smtp server provide by mosip** ---
**Author:** ![mengleang-ngoun](https://dub1.discourse-cdn.com/flex017/user_avatar/community.mosip.io/mengleang-ngoun/32/568_2.png) [@mengleang-ngoun](https://community.mosip.io/u/mengleang-ngoun)\ **Post date:** [September 13, 2023, 7:35am UTC](https://community.mosip.io/t/kernel-notifier-couldnt-install/753/4 "2023-09-13T07:35:42Z")
Thank you, Now it work. I set **mosip.kernel.mail.proxy-mail=false** in kernel-default.properties ---
**Author:** ![sanchi-singh24](https://dub1.discourse-cdn.com/flex017/user_avatar/community.mosip.io/sanchi-singh24/32/538_2.png) [@sanchi-singh24](https://community.mosip.io/u/sanchi-singh24)\ **Post date:** [September 13, 2023, 8:03pm UTC](https://community.mosip.io/t/kernel-notifier-couldnt-install/753/5 "2023-09-13T20:03:58Z")
Hey @mengleang-ngoun It’s great to hear that the issue is resolved and our team was able to guide you for any further issues coming up you can initiate a new thread and will help you out. Best Regards, Team MOSIP ---
**Author:** ![sanchi-singh24](https://dub1.discourse-cdn.com/flex017/user_avatar/community.mosip.io/sanchi-singh24/32/538_2.png) [@sanchi-singh24](https://community.mosip.io/u/sanchi-singh24)\ **Post date:** [September 13, 2023, 8:04pm UTC](https://community.mosip.io/t/kernel-notifier-couldnt-install/753/6 "2023-09-13T20:04:05Z")