Able to receive e-mail in mail-receiver but NOT in Discourse?

Product Support Self-hosting
6

Happy to clarify :slightly_smiling_face: and will pretend my domain is thesite.org for simplicity. What I do see, is a SSL issue in the mail-receiver logs:
<19>Nov 25 19:11:29 receive-mail[160]: Failed to POST the e-mail to https://inbound.thesite.org/admin/email/handle_mail: hostname "inbound.thesite.org" does not match the server certificate (OpenSSL::SSL::SSLError)

To answer your question though, I had two goals which I presume are extremely common:

  1. admin@thesite.org becomes an address for users to contact the admin
  2. thesite.org launches the forum (no subdomain)

Presently my namecheap DNS settings look like this (TTL = Auto and Priority = 10):

1   A Record   @                  (IP address)     
2   A Record  inbound.            (IP Address)    
3   CNAME     email.mg.           mailgun.org.   
4   CNAME     inbound.            thesite.org.   
5   CNAME     www.                thesite.org.    
6   TXT       @                   forward-email=(stuff)
7   TXT       mg                  v=spf1 include:mailgun.org ~all
8   TXT       smtp._domainkey.mg. k=rsa; p=(stuff)
9   MX        @                   mx1.forwardemail.net.  
10  MX        @                   mx2.forwardemail.net.
11  MX        inbound.            thesite.org.
12  MX        mg.                 mxa.mailgun.org.
13  MX        mg.                 mxb.mailgun.org.

My containers/mail-receiver.yml settings are::
MAIL_DOMAIN: inbound.thesite.org
DISCOURSE_MAIL_ENDPOINT: 'https://thesite.org/admin/email/handle_mail'
DISCOURSE_API_KEY: (stuff)
DISCOURSE_API_USERNAME: system ← same as API key
* note—> I left the LetsEncrypt lines as-is (did not remove the “#”)

Other settings:

  • changed via command line the hostname to inbound.thesite.org
  • contact email = admin@thesite.org
  • notification email = noreply@mg.thesite.org
  • reply-by email1 = replies+%{reply_key}@inbound.thesite.org
  • reply-by email2 = %{reply_key}@inbound.thesite.org
  • find related post with key = ON
  • manual polling = ON
  • mailgun API key = ENTERED …but this might be a problem because its from a previous install attempt
  • Settings > Emails > Settings: Address = smtp.mailgun.org
  • Settings > Emails > Settings: Port = 2525
  • Settings > Emails > Settings: user_name = postmaster@mg.thesite.org

Any thoughts on where I go from here? …and a huge THANK YOU in advance! Pinging also @pfaffman as he has also so kindly been a resource helping me with past struggles involving setup. Your “Straightforward” guide was extremely useful too. Cheers!