We are using Oqtane 3.4.2 and 2sxc 15.08.00. We have configured a contact form. If we send a Message we receive an error "An unexpected error occured while sending. Please try again. If it fails again, please send it by E-Mail.".
We try debugging. The exception is throwing in the method "FormController.ProcessForm()". The line is "foreach(var file in...". We have configured no files to upload.
My guess is that your Oqtane doesn't have the mail server configured yet. could you check?
You can also find more details about the error in the logs/insights - see https://docs.2sxc.org/net-code/debug/insights.html