Overview

This article provides the resolution to an issue where large emails sent on a Microsoft Exchange server are not being delivered, and instead, they are moved to the EmailSecurity or the AntiSpam FailedMails folder.

In the TNEF2MIME.gfi_log.txt file, the following error message is logged:

2013-07-05,10:48:23,083,1,"#00001660","#00002fa8","error ","TNEF2MIME","Error 103 - aborting"
2013-07-05,10:48:23,083,1,"#00001660","#00002fa8","error ","TNEF2MIME","Exiting CTnef2MimeImpl::tnef2pfi (103) [0x80004005]"
2013-07-05,10:48:23,083,1,"#00001660","#00002fa8","error ","TNEF2MIME","Converting from TNEF to PFI...FAILED (103) [0x80004005]"

Information

Environment

• GFI MailEssentials 
• Microsoft Exchange server

Root Cause

Emails which are sent on Microsoft Exchange servers are formatted in TNEF. In order for GFI MailEssentials to process such messages, they need to be converted into the MIME email format first. The conversion requires the TNEF message size to be loaded into the memory. To protect the system from a memory overrun, the default maximum size of TNEF emails is set to 50 MB. If the email is larger, it will be stored into the EmailSecurity or the AntiSpam Failedmails folder. The registry key supports message sizes up to 200 MB.

Process

1. Navigate to Start > Run type regedit and press Enter.
2. Navigate to HKLM\SOFTWARE\Wow6432Node\GFI\MailEssentials\EmailSecurity\Config and HKLM\SOFTWARE\Wow6432Node\GFI\MailEssentials\AntiSpam\Config
3. Create a new DWORD named T2Mmaxmsgsize.
4. Right-click the new value and select Modify.
5. Enter the maximum size in bytes (decimal). The maximum value supported is 209715200.
6. Navigate to Start > Run, and type Services.msc
7. Restart the GFI MailEssentails services.