Hello. I need help.
Recently, I sent a newsletter to 1000 subscribers. A significant proportion (ca. 75%) of them received an email with links starting with http://127.0.0.1/?nltr=….
The rest subscribers received an email with the correct server name http://mydomain.com/?nltr=….
What could be the reason for this strange situation?
How can I force the domain name in tracing links?