Why do the phishing e-mails I forward to my banks come back to me as undelivered?
My bank wants me to forward phishing emails to them.
However, on every occasion the messages are returned to me as undelivered mail.
is it possible this is due to security within Thunderbird?
ప్రత్యుత్తరాలన్నీ (1)
There should be a Reason for the return attached to the messages. Email servers reject messages. Thunderbird did it's part and sent it. Contact the provider that rejected it and ask them.