I have been running MiaB for a few months on a new box and everything has been fine. However, for the last few days if I log in via roundcube I see new mail but when my phone checks it cannot find anything new!
Any ideas what may be going wrong? I watch the mail.err and mail.log files whilst checking via the phone and I can see it connecting, just doesn’t download any new headers!
Cheers
Can you check the logs on your phone to ensure it is actually connecting to the MIAB properly?
Or, restart the phone. 
Sorry for the delay getting back - after reading logs after logs and checking the phone, I found it was actually the app I was using (K9 on Android) that decided it didn’t want to play nice.
Installed another client and everything is happy!
Must be one of your settings, I use our MIAB with K9 just fine. Thought I would share in case you ever want to try the app again.