If you are seeing emails automatically being encrypted without selecting encryption, there can be two reasons for this.
Replying to an Encrypted Email
You are replying to an encrypted email. If the email you are replying to or forwarding is a secure email, even if you select to send unencrypted, it will still be sent securely.
Default Microsoft Outlook Add-In Settings
By default, the Microsoft Outlook add-In automatically encrypts emails with attachments over 10MB. This threshold can be customized using a registry key.
Note:Depending on your permission settings, you may need to request these changes from your IT department.
To change the 10 MB auto encrypt feature:
- Open Regedit. To do this, select the Start button. In the Start Menu, in either the Run or Search box, type "regedit" and press Enter or Return.
- Navigate to HKEY_LOCAL_MACHINE\Software\Egress\Switch and HKEY_LOCAL_MACHINE\Software\Wow6432Node\Egress\Switch.
- Right-click in the white space on the right-hand side of Regedit, underneath (Default), and create a DWORD called “LargeFileMinKB”.
- When adding the Value, change the “Base” to “Decimal” to add the size you would like to change to in bytes. For example, 30000 Decimal will be just under 30 MB.