Forum Discussion
Emails Received from Thunderbird on Exchange 2013 CU23 get their attachments corrupted
We are facing an issue with emails received from specific people using Thunderbird mail client and sending attachments in languages other than English. The email is received ok . Content is fine and...
I can reproduce this as soon as Thunderbird is connected by e.g. GMX and the delivery format is set to auto-detect or "plain and Rich (HTML) Text".
If I use "plain Text Only" or "Rich Text (HTML) Only" the attachment is received correctly by Outlook.
We have Exchange 2016 CU19 and Outlook 2016.
ckessing
Thanks for the feedback!
I found the issue..
The last part of the maiflow wasn't TLS encrypted! Enabling TLS on the receive connector fixed the issue!
Although they told me no network device in between could have modified any packets, and they don't have IPS configured, something was able to change the packets I guess.