I use Mac Mail. A Thunderbird user sends me emails with Undisclosed Recipients and images as text
I am part of a group. A new member has joined the group and he is a Thunderbird user. Some of the group can use Reply All to his emails because all the group are listed in his header, some but not all of the Mac Mail users cannot do this as his email only displays his address and "Undisclosed Recipients". Also attached images are displayed as text in Mac Mail. Are there Thunderbird or Mac Mail settings that can solve this? Thanks Rex
All Replies (4)
"Undisclosed recipients" is inserted into the message by Thunderbird when Bcc (Blind Copy) is used.
So, is the new member consistent in his use of Bcc? What's the group policy on sharing your email addresses between you? Should he be using Bcc or not?
I'd like to think that if Bcc is used, no-one but the sender would see the addresses that were set as Bcc. But there is anecdotal evidence that some servers are configured to share Bcc addresses amongst Bcc recipients.
The handling of Bcc should be a function of the sender's SMTP server. It should issue a copy of the message to each Bcc recipient, and it should strip the Bcc information from these copies. I'd be really surprised if the recipient's email client had any relevance.
We might surmise that if the sender's SMTP server is leaking Bcc addresses, then maybe some clients take it on themselves to redact these Bcc addresses and other clients don't. But this is pure guesswork; I don't think there is anything in the relevant standards that asks email clients to do this when receiving incoming mail.
He is not using Bcc and has checked. He screen grabbed the header to show me, and sent it via Gmail, second problem :-) Some of the group can see and use "Reply All". Some of the group can only see his email address and "Undisclosed Recipients" so "Reply All" does not work.
That kind of suggests that some other server is redacting recipients' addresses and inserting the "Undisclosed Recipients". I have never heard of such a thing.
Are these long lists of addressees? How many, typically? I wonder if your list is long enough to trip a masking action on some servers but not others?
My test message Bcc'd to myself (at three different addresses) was sent with
undisclosed-recipients:
in the To: field, so this was put there by Thunderbird itself. Does the header in your member's messages look EXACTLY like this? Same hyphenation, all lower case, with a colon?
As Attached There are 10 members in the group. This is what I receive in my email from Eric.
When he sends it from Gmail the group addresses all show
