Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More
Cuireadh an snáithe seo sa chartlann. Cuir ceist nua má tá cabhair uait.
Cartlannaithe

A Windows 10 update this week has caused blind copies to be sent showing recipients e-mail address and I don't know how to solve this.

Devonchris replied
Devonchris

The update caused a problem with sending e mails which I resolved with help but now I cannot send to several people without all addresses being shown as well as their address book names even when I use BCC.

The update caused a problem with sending e mails which I resolved with help but now I cannot send to several people without all addresses being shown as well as their address book names even when I use BCC.

All Replies (3)

How many accounts do you have? Are they all with the same provider? Do they all behave in the same way?

I ask because I'd suspect the server you're using is part of this problem. I am not seeing other users complaining about this, and my own test messages using Bcc all work properly (apart from a known problem with "Unknown recipients:" being omitted.)

Some email providers do not support Bcc. It's criminal that they don't actually tell you that something you expected to be private will not be treated with the respect it deserves.

I am not aware of any adjustments in Thunderbird that would disable Bcc. That's why I think your problem is due to an external cause.

Sorted thank you. Looks like an update and change of display format caused the confusion for me.

Thanks. Have sorted it now.