[MM3-users] Re: Block members from sending cc's and bcc's

On 6/23/25 10:04, Cathryn McGuire wrote:

Hi everyone,

Using Mailman 3 with Affinity web interface and we want to stop our members from sending to cc: or bcc:

You won't ever see a Bcc: header in mail to a list. The whole point of Bcc: is to not expose the additional recipients or the fact that there were additional recipients so the sending MUA includes the Bcc recipients in the SMTP RCPT TO commands, but drops the Bcc: header from the message.

I.e., There is no way to know whether the original sender included Bcc: recipients or not.

-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan