We have an Exchange Hybrid configuration.
When outlook clients receive a Rich text format e-mail and reply the format stays Rich text.
When the Outlook client sends the Rich text format e-mail with embedded image to internal Exchange 2016 CU17 server they get an NDR reply.
'Corrupt message content; STOREDRV.Deliver.Exception:ConversionFailedException.ConversionFailedException.TextConvertersException; Failed to process message due to a permanent exception with message The message content has become corrupted. ConversionFailedException: Content conversion: Body conversion failed. [Stage: PromoteCreateReplay]
When the Outlook client gets outside the office and connect to Exchange Online, they have no problem.
When they return inside the office the problem stays away and never returns.
Anyone with the same problem?
Two DAG Exchange 2016 CU17 servers on Windows server 2016.
Microsoft Office 365, Outlook 2013 and Outlook 2016 Clients.