Target mail address in bcc header is not detected for incoming mail

Thomas_Rother · February 17, 2025, 7:29am

Use case: Incoming mail should be copied into a discourse topic through bcc. DIscourse receives this mail from the mailserver through pop3.

The mailserver has a recipient_bcc_maps table (see http://www.postfix.org/postconf.5.html#recipient_bcc_maps) which adds a bcc header with a discourse+extension target address.

But the incoming mail is rejected by current Discourse 3.5.0.beta1-dev with error msg

Email::Receiver::BadDestinationAddress](https://forum.netzwissen.de/admin/email/rejected)

It looks as if Discourse only reads the to and/or cc. fields, but not bcc. Therefore it does not detect the correct discourse+extension address.

See also old topic Email with correct incoming email address in bcc is being rejected

zogstrip · February 24, 2025, 3:49pm

It should check bcc header as per

github.com/discourse/discourse

lib/email/receiver.rb

2062e4eb9


      
          def get_all_recipients(mail)
            recipients = Set.new
          
            %i[to cc bcc].each do |field|
              next if mail[field].blank?
          
              mail[field].each do |address_field|
                begin
                  address_field.decoded
                  recipients << address_field.address.downcase
                end
              end
            end
          
            recipients
          end

Mind sending me the raw email via PM (PII removed is better) so that I can check it?

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Target mail address in bcc header is not detected for incoming mail

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