Knowledge Base

How to disable image compression in Outlook

Problem:

Outlook reduces the quality of images in emails. This can also affect graphics in email signatures added by CodeTwo software.

Solution:

By default, the Outlook desktop app on Windows applies image compression to reduce email size.

Starting with Outlook for Microsoft 365 version 2109, image compression can be turned off in Outlook settings so that images in your email signatures don’t get modified and appear as you intended. However, there is no way to force images to keep their quality once an email is sent. This means that if anybody forwards or replies to your email, the quality of images found in the thread might get worse despite the settings used on your end.

To prevent Outlook from applying image compression:

  1. In Outlook, go to File > Options.
  2. On the Mail tab, click the Editor Options button.
  3. On the Advanced tab, under Image Size and Quality:
    • select the Do not compress images in file checkbox
    • set the Default resolution option to High fidelity
    and click OK (Fig. 1.).

Disabling image compression in Outlook for Windows.
Fig. 1. Disabling image compression in Outlook for Windows.

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