I have Zentyal 6.1 installed on Ubuntu 18.04 and since upgrading to 6.1 from 6.0 I am having issues with a select few ActiveSync clients on Android.
When attempting so to send mail with any attachment, I get the message that the email is to big to be sent. Strangely this behaviour is immediate and not after attempting to transmit.
On Outlook 2016 it works 100%.
Any ideas where I might start looking for the issue?