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SeaMonkey 2.53.8.1

  -  50.4 MB  -  Open Source
Free Download

Security Status

Sometimes latest versions of the software can cause issues when installed on older devices or devices running an older version of the operating system.

Software makers usually fix these issues but it can take them some time. What you can do in the meantime is to download and install an older version of SeaMonkey 2.53.8.1.


For those interested in downloading the most recent release of SeaMonkey for Mac or reading our review, simply click here.


All old versions distributed on our website are completely virus-free and available for download at no cost.


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If you have any questions or ideas that you want to share with us - head over to our Contact page and let us know. We value your feedback!

Download SeaMonkey 2.53.8.1

  • SeaMonkey 2.53.8.1 Screenshots

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    SeaMonkey 2.53.8.1 Screenshot 1
  • SeaMonkey 2.53.8.1 Screenshot 2
  • SeaMonkey 2.53.8.1 Screenshot 3
  • SeaMonkey 2.53.8.1 Screenshot 4
  • SeaMonkey 2.53.8.1 Screenshot 5

What's new in this version:

SeaMonkey 2.53.8.1 contains (among other changes) the following major changes relative to SeaMonkey 2.53.8:
- Archive message action does not work
- Do not preserve offlineMsgSize parameter when moving/copying emails between folders and
- Move thread code to threadPane.js and remove messengerdnd.js

SeaMonkey 2.53.8.1 contains (among other changes) the following major changes relative to SeaMonkey 2.49.5:
- The Bookmarks Manager has switched its name to Library, and now also includes the History list. When invoking History, the Library will be shown with the History list selected. The extensive modifications were needed because of Mozilla Gecko platform API changes.
- Download Manager has been migrated to a new API. Although it looks pretty much the same as before, the search option is missing and some other minor details work differently. The previous downloads history is removed during the upgrade.
- The layout panel was added to the CSS Grid tools
- TLS 1.3 is the default SSL version now
- Support for all NPAPI plugins like Flash, Java and Silverlight has been removed. For displaying pdf files in the browser you can use pdf.js-seamonkey from Isaac Schemm.
- SeaMonkey now uses a new api for formatting regional data like time and date. Default is to use the application locale of the current SeaMonkey build. If you use a language pack or a different OS formatting this is usually not desired. You can change the formatting from the application locale to the regional settings locale (OS) in the preferences dialog under "Appearance".
- SeaMonkey 2.53.8.1 uses the same backend as Firefox and contains the relevant Firefox 60.8 security fixes
- SeaMonkey 2.53.8.1 shares most parts of the mail and news code with Thunderbird. Please read the Thunderbird 60.0 release notes for specific changes and security fixes in this release.
- Additional important security fixes up to Current Firefox 78.12 ESR and a few enhancements have been backported. We will continue to enhance SeaMonkey security in subsequent 2.53.x beta and release versions as fast as we are able to.

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