checksum calculated for fmail3 is incorrect, yet the app updates just fine through Sparkle

### `brew config` AND `brew doctor` output OR `brew gist-logs <formula>` link ```shell Please note that these warnings are just used to help the Homebrew maintainers with debugging if you file an issue. If everything you use Homebrew for is working fine: please don't worry or file an issue; just ignore this. Thanks! Warning: Some installed casks are deprecated or disabled. You should find replacements for the following casks: macupdater Warning: The following repositories are on the deprecated "master" branch. The "master" branch sync will stop and this warning will become an error when Homebrew 5.2.0 is released (no earlier than 2026-06-10). Run `brew update` to migrate to "main": homebrew/autoupdate ``` ### Verification - [x] My `brew doctor` output says `Your system is ready to brew.` and am still able to reproduce my issue. - [x] I ran `brew update` and am still able to reproduce my issue. - [x] I have resolved all warnings from `brew doctor` and that did not fix my problem. - [x] I searched for recent similar issues at https://github.com/Homebrew/homebrew-core/issues?q=is%3Aissue and found no duplicates. - [x] My issue is not about a failure to build a formula from source. ### What were you trying to do (and why)? I was trying to update fmail3 from version 2.5.0 to 2.5.1 in homebrew using the "forced" parameter because this app has a Sparkle updater incorporated. The app updates just fine using the Sparkle updater, but homebrew declares a checksum error. ### What happened (include all command output)? This is the output: ==> Upgrading fmail3 to 2.5.1 ✘ Cask fmail3 (2.5.1) Verifying 3.5MB/ 3.5MB Error: Cask reports different checksum: 3012b784af8ecf2c2fe6fcbcf8113e41bdfe4838eb963cf8a7378c88be039f9a SHA-256 checksum of downloaded file: 52a05bd8dae5c77d22f59d4018fea10db16b2a16f0702391a652aede256e4a7e ==> Fetching downloads for: fmail3 ✘ Cask fmail3 (2.5.1) Verifying 3.5MB/ 3.5MB Error: Cask reports different checksum: 3012b784af8ecf2c2fe6fcbcf8113e41bdfe4838eb963cf8a7378c88be039f9a SHA-256 checksum of downloaded file: 52a05bd8dae5c77d22f59d4018fea10db16b2a16f0702391a652aede256e4a7e Error: Failed to upgrade fmail3 ### What did you expect to happen? I expect fmail3 to be upgraded (or installed) to version 2.5.1 ### Step-by-step reproduction instructions (by running `brew` commands) ```shell I tried uninstalling ("brew uninstall fmail3") and then reinstalling ("brew install fmail3"), but I see the same error. mbizer@MacBookPro ~ % brew install fmail3 ==> Fetching downloads for: fmail3 ✘ Cask fmail3 (2.5.1) Verifying 3.5MB/ 3.5MB Error: Cask reports different checksum: 3012b784af8ecf2c2fe6fcbcf8113e41bdfe4838eb963cf8a7378c88be039f9a SHA-256 checksum of downloaded file: 52a05bd8dae5c77d22f59d4018fea10db16b2a16f0702391a652aede256e4a7e ```