SMTP issue – stopped working

I had SMTP Configure plugin working and sending emails out and now it seems to have just stopped. I haven’t changed any settings in the plugin.

The error it comes up with is “Could not connect to SMTP host” and its a similar message on other SMTP plugins. I can’t understand what I need to do or change (the email, password, ports, etc are all correct).

The only thing that I have changed is I have added a couple of contact form plugins but I have taken them off and still nothing.

Thanks