We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

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

Can't send Bcc anymore

  • 41 replies
  • 5 have this problem
  • 1 view
  • Last reply by tiger-rka07

more options

I've used Thunderbird for many years, problem free. Suddenly, when trying to send a Bcc email, I get this:

Sending of the message failed.

The message could not be sent using Outgoing server (SMTP) smtp.cox.net for an unknown reason. Please verify that your Outgoing server (SMTP) settings are correct and try again.

I've used Thunderbird for many years, problem free. Suddenly, when trying to send a Bcc email, I get this: Sending of the message failed. The message could not be sent using Outgoing server (SMTP) smtp.cox.net for an unknown reason. Please verify that your Outgoing server (SMTP) settings are correct and try again.

All Replies (1)

more options

Content is usually just text but in the past I've never been restricted in any way as to Bcc content. I have removed all anti-virus programs except Windows Defender and it has been that way for at least a year. Yes, it says 'True'.

  1. 1
  2. 2
  3. 3