Steps to reproduce:
- Set up an email capturing software, like FakeSMTP. It's default listening port is 2525
- Start up 6.2 EE
- At Control Panel > Server Administration > Mail, set the Outgoing Port to 2525
- Create a user named "A"
- Add Admin roles to the user
- With Test, add a Message Boards Portlet to a page and create a category
- Log in with "A" user, add a new thread to the created category with message: "First message"
- Reply to this message with "Second message"
The user receives an email notification about their second message, but not for the first one,with whom they opened the thread.
The user should receive email notifications for both the initial message and it's reply message
If the user places a breakpoint to SubscriptionSender.flushNotifications() they receive notification email for both messages.