Continuing the discussion from Replacing Mailing lists: Email-In:
Sorry if this is already discussed. It’s rather hard to search for the 2-character “CC” on Discourse. 
Is there (ever or still) a valid reason to reject emails where the Discourse email address is on the CC or BCC line? If so, what’s the rationale? We have had this happen a few times recently with confused users.
I was asked about this on Monday. A user wanted to send an email to a consultant with a cc to our staff mailing list on discourse. The idea she had (I think) was to enable staff to reply to both consultant and staff for follow up.
This doesn’t have predictable results and so I encouraged her to write two separate emails. One to staff and another to the consultant. Otherwise if the consultant replies all it will generate an error from discourse, and the replies from the staff won’t get to the consultant.
Discourse and email are like oil and water, sadly. But folks are getting used to it and we’re getting good results.
Our scenario is quite similar. The questions come from addresses (aliases) associated with specific categories that are handled like team distribution lists, like yours.
Seems to really confuse users. How best to improve the experience? At a minimum, I think the error message here could be improved.
OK, what does it currently say and what do you think it should say?
Discourse fires off the “I didn’t recognize that To: address” error reply if it’s in the CC:.
Here’s an important question: What part of the email should be posted?
It will be difficult to strip out the email addresses from the “Forwarded Message” block, as (of course!) every email client will do it differently.
If it is not wanted to let in emails send to a category through Cc: or Bcc: I at least want to suppress the reject email. What do you think?
Reason is I currently try to move people away from using email and get them used to Discourse. So I let Discourse harvest emails send to some mailinglists. As soon as there is such an mailinglist address added to the Cc: field instead of To: the sender gets confronted with the reject email send by Discourse. This is confusing people.
Has there been any change in this behavior with 1.5, @zogstrip?
When an email is received, we look for email addresses in all the destinations fields (To, Cc and Bcc). If at least one matches a reply address, a group or a category incoming email address, then the mail will be processed.
Quizás me esté perdiendo algo, pero ¿no existe tal cosa como una cabecera Bcc?
Sí veo que el código fuente de Discourse la está verificando, pero ¿no es la idea detrás de Bcc que esas direcciones de correo electrónico nunca deben aparecer en una cabecera?
BCC es una opción de encabezado válida; si la dirección del destinatario no estuviera en el encabezado, el mensaje no podría llegar a ellos.
Una vez que un correo electrónico con múltiples destinatarios llega al MTA, se envía por destinatario. Los usuarios en “to/cc” verán un encabezado sin BCC, mientras que cualquier usuario con BCC verá su dirección especificada como BCC:
El enrutamiento se realiza según el sobre RFC821; las cabeceras del mensaje no se utilizan para ello.
He realizado más investigación y, efectivamente, existe una cabecera Bcc en la especificación, pero nunca la he visto utilizada.
En la práctica, los MTA y/o los clientes de correo parecen omitir la cabecera Bcc en los mensajes, incluso cuando se entregan a uno de los destinatarios en Bcc.
Esta es también mi experiencia. No recuerdo haber visto nunca mi dirección de correo electrónico en un mensaje que me fue enviado en Bcc.
@zogstrip, ¿sabrías qué podría estar ocurriendo?
Parece que antes había una verificación en el sobre en este commit: add support for incoming emails in CC/BCC fields · discourse/discourse@93d1cc6 · GitHub (específicamente discourse/lib/email/receiver.rb at 93d1cc6294085008e025bb3032b231a6a81c6480 · discourse/discourse · GitHub), pero parece que luego se refactorizó en versiones más recientes de receiver.rb.
¿Existe alguna posibilidad de que los cambios que @k4rtik destacó vuelvan a implementarse? Recientemente me he encontrado con este problema. Nuestros usuarios desean enviar actualizaciones mediante BCC.