Invalid TNEF message.

Question

Hi Rebex Support Team,

We have the licensed version of Rebex Secure Mail which we purchased in the month of May 2015.

Recently for certain emails we are getting an exception of - "Invalid TNEF message".

Note: -
When we are processing such emails from our Inbox we are getting the following exception message - "Invalid TNEF message" but if we forward those emails to some other email accounts and then we try to process those forwarded emails through Rebex, we do not get any exceptions.
If required can we have a screen sharing session for the same? Please let us know your preferred time.

On your support forum we found that this issue was resolved in the version of Rebex Secure Mail 2012 R2.

So, kindly help us to resolve this issue

Answer 1

Well, if you forward the message, some mail servers along the way have a habit of modifying the emails so after you parse it second time, the invalid TNEF part might have already been removed. That's most probably why you only get the error at the original server.

I checked your dlls and they are version 5584 (e.g. 2015 R3.1).
There has been some more enhancements when processing the TNEF emails since then.

So first of all, could you please try updating to the latest version of Rebex Secure Mail and if you still get the "Invalid TNEF message" exception with it on the original server, then please download the message as is via the GetMessage method:

client.GetMessage(id, "email.eml");

and then zip it and send it back to us for analysis to support@rebex.net

Comments

Hi Tomas,

As per your suggestion, we have updated the latest version of Rebex Secure Mail (i.e. Release 2016 R1.1) but still we are getting the same exception - "Invalid TNEF message".

So, using the GetMessage method the original email message is downloaded as InvalidTNEFMessage.eml and sent to "support@rebex.net" for further analysis.

Please check and let us know the solution asap

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I have just sent you an email response. It includes link to hotfix version which contains workaround for your TNEF message.
Problem is that the TNEF message ends prematurely, so the parser failed. The workaround tries to extract as much as possible data from the invalid TNEF.