Wow. No idea what changed...

[Technical Ben]

... but my IDNet email accounts are now coming through on Mozilla Thunderbird. Not checked the online access/web portal yet as that was giving me errors before, but will check it out soon.
My emails are showing from this time last year, so for some reason it's been stuck since then.  

(Might have been an error my end, but looks like the recent repairs/reboot to the email server has sorted stuff out anyhow, so I'm happy!)