Reproduction Pre-Requisites

1. An otherwise unused e-mail account which supports:
   1. IMAP
   2. Sub-Addresses
2. Working SMTP configuration for Moodle
3. A course, with at least one student enrolled (the student must have a working e-mail address that you can check)
4. Access to run cron

Reproduction setup

1. Login as administrator
2. Open Site administration -> Server -> Incoming mail configuration -> Mail settings
3. Enter your mailbox configuration:
   1. Mailbox name: The bit before the @ on the e-mail address you would use to send e-mail to. For example, jammydodger in jammydodger@example.com
   2. Email domain: The bit after the @ on the e-mail address you would use to send e-mail to. For example, example.com in jammydodger@example.com
4. Enter your Incoming mail server settings
   1. Incoming Mail Server: The IMAP server name
   2. Use SSL: Server-dependent
   3. Username: The username required to log on to this IMAP server
   4. Password: The password required to log on to this IMAP server
   5. Click Save changes
5. Open Site administration -> Server -> Incoming mail configuration -> Message handlers
6. Click the Edit icon beside "Reply to forum post"
   1. Place a tick beside "Enabled"
   2. Ensure that "Validate sender address" is disabled
   3. Click Save changes

Reproduction procedure

1. Login as an editing teacher and navigate to your the course created for this test
2. Create a new discussion forum with automatic enrolment
3. Post a new discussion in this forum:
   1. Ensure that you check the "Mail now" option
4. Run cron
5. Check the e-mail account of your student user
6. You will have recieved mail from somone called "Do not reply to this email"