Blueyonder email not being delivered to Blueyonder addresses

As you and many others have found, blueyonder email has become very unreliable. No one knows how much longer it will continue. You really should think about changing to another email provider. 

If any of those people no longer have Virginmedia broadband accounts, their blueyonder emails will have been closed by VM. That will explain why they are not getting your email. 

There is a VM help page on bulk emails below

https://www.virginmedia.com/help/billing-and-payments/how-to-send-an-email

You could see if anything there helps. It may not be any use for your problem though. As jpeg1 has already stated, VM's email service is not really fit for even the most emailing tasks.

AliMill wrote:
⋮
To avoid making the addresses of the group members public, I do this by sending the message to my Blueyonder address and cc to the addresses of group members.
⋮

Is CC a typo, i.e. did you mean BCC?

What happens when you just BCC those 2 email addresses?

FWIW if email is important to you then do heed the good advice to migrate away from Virgin Media's email services

AliMill​ 

"Two members who have Blueyonder addresses do not receive my messages. Others with Blueyonder addresses do receive my messages." 

That seems to suggest that it's something with those two Blueyonder email accounts that's causing the problem

If I was in your position I would try to trouble shoot the problem by:

1) I would start by:

• asking both of those members to send a test BY email to your Blueyonder account
• then send an email back to each of them using the "Reply" option rather than by creating a new message.
• then check with each of them whether they get your reply.

If they do, the first thing to check is that you have been sending the BCC's to their correct address. If they don't then move on to:

2) " the recipients have not blocked me."

Just for information, even if those recipients have added your email address to the "Blocklist" in the Blueyonder accounts they would still be getting your emails, That so called "Blocklist" function in BY/VM webmail merely flags emails from a "Blocked" email address as spam. It does not stop them from arriving in their BY email account, 

However, you do need to check whether they have any Filter rules set up in their BY accounts. It may be that your emails are inadvertently being "Discarded" by a filter rule they set up to stop spam emails arriving in their BY accounts. If they do have any rules set up ask them to temporarily disable the rules and then resend one of your former emails and to your contacts as BCC addresses. If that test email gets through it strongly suggests it's your contact's filter rule that's blocking your emails.

See how all that goes and post back with the results.

Coenoby