Specify default quality of compression done on inlined images inserted in Outlook: registry value oulookimagedpiindexUserHKCU\software\policies\microsoft\office\16.0\common\mailsettings

Policy ID: L_DefaultCompressionQualityForInlinedImagesInOutlook
Scope: User Configuration
Supported on: At least Windows Server 2008 R2 or Windows 7
Source: Microsoft 365 Apps / Office Administrative Templates (version 5568.1000)
Category: Microsoft Word 2016 › Word Options › Advanced › E-mail Options

Registry

oulookimagedpiindex

REG_DWORDUser

HKCU\software\policies\microsoft\office\16.0\common\mailsettings Current key

Enabled value: Depends on the option value
Element: Default inline image compression quality for Outlook:

Options
Item	Stored value
High Fidelity	0
330 ppi	1
220 ppi	2
150 ppi	3
96 ppi	4

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\common\mailsettings]

; Options (use only one)
; High Fidelity
"oulookimagedpiindex"=dword:00000000
; 330 ppi
"oulookimagedpiindex"=dword:00000001
; 220 ppi
"oulookimagedpiindex"=dword:00000002
; 150 ppi
"oulookimagedpiindex"=dword:00000003
; 96 ppi
"oulookimagedpiindex"=dword:00000004

CMD

:: Options (use only one)

:: High Fidelity
reg add "HKCU\software\policies\microsoft\office\16.0\common\mailsettings" /v "oulookimagedpiindex" /t REG_DWORD /d 0 /f
:: 330 ppi
reg add "HKCU\software\policies\microsoft\office\16.0\common\mailsettings" /v "oulookimagedpiindex" /t REG_DWORD /d 1 /f
:: 220 ppi
reg add "HKCU\software\policies\microsoft\office\16.0\common\mailsettings" /v "oulookimagedpiindex" /t REG_DWORD /d 2 /f
:: 150 ppi
reg add "HKCU\software\policies\microsoft\office\16.0\common\mailsettings" /v "oulookimagedpiindex" /t REG_DWORD /d 3 /f
:: 96 ppi
reg add "HKCU\software\policies\microsoft\office\16.0\common\mailsettings" /v "oulookimagedpiindex" /t REG_DWORD /d 4 /f

PowerShell

# Common: create the key
New-Item -Path 'HKCU:\software\policies\microsoft\office\16.0\common\mailsettings' -Force | Out-Null

# Options (use only one)
# High Fidelity
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\common\mailsettings' -Name 'oulookimagedpiindex' -PropertyType DWord -Value 0 -Force | Out-Null
# 330 ppi
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\common\mailsettings' -Name 'oulookimagedpiindex' -PropertyType DWord -Value 1 -Force | Out-Null
# 220 ppi
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\common\mailsettings' -Name 'oulookimagedpiindex' -PropertyType DWord -Value 2 -Force | Out-Null
# 150 ppi
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\common\mailsettings' -Name 'oulookimagedpiindex' -PropertyType DWord -Value 3 -Force | Out-Null
# 96 ppi
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\common\mailsettings' -Name 'oulookimagedpiindex' -PropertyType DWord -Value 4 -Force | Out-Null