I use posteo so it is this address: https://posteo.de:8443/ …
I don’t have any security software running which would block connections.
To me it makes no sense, that some events are synchronized, but some are obviously an old version (deleted events still appear) and one of three calenders doesn’ sync at all.
I tried to get logs. But I didn’t manage: I installed android-SDK-linux on my computer and started the USB-debugging mode on the Fairphone, and run Dmms however, when I use the command > Device > run logcat I get the message “failed”. I couldn’t get adb running as describes in the link. However, dmms should use adb anyway?