Check with your webhosting company -many have facilities for amiling lists to go direct from their servers, bypassing O2's involvement.
I don't know CLick-it, but certianly the last 3 hosting companies i've used have offered the facility.
What is ransomware and how do I protect my PC from WannaCry?
Disney layout supervisor Rob Dressel on the challenges of visualising Moana
Siri vs Google Assistant
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.