I've noticed a rather significant number of mail servers delaying or blocking mail from midrange.com.
I would encourage you to contact your mail administrator and whitelist midrange.com for mail delivery.
midrange.com's mailing list are confirmed using a closed-loop authentication system, so nobody can be subscribed to a list without their authorization.
midrange.com uses the following IP block: 188.8.131.52-45 (CIDR 184.108.40.206/28). All messages are signed with DomainKeys & DKIM and SPF records are published in DNS.
If you have any questions, feel free to contact me at support@xxxxxxxxxxxx.