after updating to z-push 2.3.8 some mails arrive on iPhone with empty subject. Most of this mails came from German Kopano support and contains one or more “Umlaute” in subject.
Please see this iOS 10.3.3 screen shot:
Missing subject marked with red arrow.
I see this issue only with z-push. Viewing the mails with WebApp, subject is OK.
Environment: iOS 10.3.3 or iOS 11.0.1, Kopano core: 8.3.4, SLES 12 SP2.
German Kopano support is unable to duplicate this issue.
Any ideas how to solve this issue?