There is another old post similar to this.
https://community.bt.com/t5/Email/Not-receiving-emails-with-attachments/td-p/2213805
Is there a common issue with BT accounts not receiving emails with attachments.
Unfortunately I don't have access to a BT account myself but I have a work issue reported that emails sent out from our servers are not being received. They are just standard emails with a print at home pdf attachment. The attachments are just tickets to events containing QR codes.
The issue reported was that nobody with a BT email is receiving the emails. I have confirmed sending emails to all other providers and no other email provider has an issue receiving the emails so for some reason they are being blocked by BT. I don't know why they wouldn't go into a junk folder either.
Unfortunately I can't even create an account now myself to test with my family member who has BT as BT no longer create new email addresses.
