Note an update on this issue.

It was investigated by my ISP's technical people.

They have found the problem is caused by a service they use to block IP addresses which the service provider has on various blacklists for spam abuse or other net abuse.

As they say, the listings may be caused by someone appropriating the IP address and not the owner of it etc. And that ISP often have random IP addresses within allocated ranges which users randomly get allocated when logging onto the ISP's internet connections.

However I have checked a couple of the IP addresses which recently had problems and they were not listed or blocked.

Clearly this is not an acceptable solution and what they recommended people experiencing problems do is completely unacceptable ie the individuals all need to contact the anti-spam service provider to get their IP address removed from the blocked lists. This is total rubbish and no solution at all. Clearly the 'service' is not working correctly.

Also it is confusing why it is preventing log ins, when the service purports to deal with emails.

Note this 'service' has nothing to do with NitroExpress.com, it is subscribed to by the ISP for the servers NE sits on.

A good thing though, is that the problem has not been caused by a hacker or similar, but by the ISP itself.

Annoying and bloody unacceptable.

Sorry for the inconvenience for anyone who has temporarily experienced this problem.

There is one solution available to NE ie change the ISP which the forums sit on, but hopefully the ISP will come up with something themselves soon.