# Allow reply-to individual instead of topic/forum (mailing list feature)

**URL:** https://meta.discourse.org/t/allow-reply-to-individual-instead-of-topic-forum-mailing-list-feature/44905
**Category:** Support
**Created:** [27 mei 2016 om 14:24 UTC](https://meta.discourse.org/t/allow-reply-to-individual-instead-of-topic-forum-mailing-list-feature/44905 "2016-05-27T14:24:28Z")
**Posts on this page:** 1
**Showing post:** 24

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### Author: ![tarek](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/tarek/32/124831_2.png) [@tarek](https://meta.discourse.org/u/tarek)
#### Post date: [19 juni 2016 om 23:19 UTC](https://meta.discourse.org/t/allow-reply-to-individual-instead-of-topic-forum-mailing-list-feature/44905/24 "2016-06-19T23:19:43Z")

</div>

Hello all,

I am trying to understand how to properly make this plugin. I’m currently stuck in my plugin.rb, as it seems that I cannot properly replace the MessageBuilder class.

Here is the current plugin.rb (and the repo in general):

> <https://github.com/tareko/discourse-replyto-individual/blob/master/plugin.rb>

I have tried to understand how to do this by reading a few topics I could find in searches, but as of yet no luck:

- Beginner’s Guide to Creating Discourse Plugins [1](https://meta.discourse.org/t/beginners-guide-to-creating-discourse-plugins/30515) [2](https://meta.discourse.org/t/beginners-guide-to-creating-discourse-plugins-part-2-plugin-outlets/31001) [3](https://meta.discourse.org/t/beginners-guide-to-creating-discourse-plugins-part-3-custom-settings/31115) [4](https://meta.discourse.org/t/beginners-guide-to-creating-discourse-plugins-part-4-git-setup/31272) [5](https://meta.discourse.org/t/beginners-guide-to-creating-discourse-plugins-part-5-admin-interfaces/31761) [6](https://meta.discourse.org/t/beginner-s-guide-to-creating-discourse-plugins-part-6-acceptance-tests/32619)
- [Basic plugin template](https://meta.discourse.org/t/basic-plugin-template/15511)
- [Plugin Tutorial #1 - How to manipulate the text in the composer?](https://meta.discourse.org/t/plugin-tutorial-1-how-to-manipulate-the-text-in-the-composer/10925)
- [Plugin Tutorial #3 - How to add a button after every posts?](https://meta.discourse.org/t/plugin-tutorial-3-how-to-add-a-button-after-every-posts/11050)

When I run the plugin, I get the following, which I suspect reflects that the class is not properly replaced:

```plaintext
/vagrant/lib/email/message_builder.rb:20: warning: already initialized constant Email::MessageBuilder::REPLY_TO_AUTO_GENERATED_HEADER_KEY
/vagrant/lib/email/message_builder.rb:20: warning: previous definition of REPLY_TO_AUTO_GENERATED_HEADER_KEY was here
/vagrant/lib/email/message_builder.rb:21: warning: already initialized constant Email::MessageBuilder::REPLY_TO_AUTO_GENERATED_HEADER_VALUE
/vagrant/lib/email/message_builder.rb:21: warning: previous definition of REPLY_TO_AUTO_GENERATED_HEADER_VALUE was here

```

Any thoughts or advice?

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_[View the full topic](https://meta.discourse.org/t/allow-reply-to-individual-instead-of-topic-forum-mailing-list-feature/44905)._