Sorry to hear you've had an issue receiving emails from some email addresses. If the helpful advice offered above doesn't help please let us know.
If this continues it would be helpful if you're able to get a copy of any rejected email your contact receives if possible (with full headers/no redaction's) - though don't post them here publicly, we will ask for them via PM if required.
Thanks for keeping us updated on this jackeyres. I understand it may be difficult for the teams to establish what's going wrong if there isn't any sign of the emails bouncing - however I'll be happy to ask them to take a look if you're able to get back to me via PM & confirm some details.
Sorry for the late response - virgin community emails go straight to my junk folder which I suppose is another problem. So if I offer up the date and time and sender of the emails will someone be able to work out what’s going wrong?