If I send an email to multiple addressees, each of them in a "BCC" field, I wanna make sure that each person does not know other people received that email.
For example when I ask around for a quote, it is just easier to send the same email to many BCCs. However today one of them replied asking: "who else in our company did you send it to?I just want to make sure we are not doing double work. "
Then I sent a few trial emails to friends (2 addressees both BCC) and some friends didn't see "undisclosed recipients" under the field "To" while other had it. Some had "undisclosed recipients" in the computer, some only in the phone.
How can I make sure no one sees "undisclosed recipients" in the email they receive, and that they do not know there are other addressees? I am using my university edu email, and smtp.gmail.com as outgoing server. Using Thunderbird under Windows, if all this matters.