Okay, I'll rephrase. PlusNet have absolutely nothing to do with the running or management or funding of mail2web. The previous post seemed to imply they had set it up or were somehow involved, I just want to make the distinction. Additionally they haven't 'given permission' mail2web to do anything. The service is a web-based interface to pop3/imap mail servers. Finally, mail2web is for receiving not sending. It does not give access to PlusNet's SMTP servers, which PlusNet's webmail service does. It's spamming via PlusNet's SMTP servers that the measure they have implemented is designed to limit.
I'm not defending PlusNet, but they are two different companies and this is very important. There's enough FUD around after all

There are also myriad of double-standards within PlusNet and their policies, but adding to the confusion doesn't help.