Releasing of such a complex application as eM Client is not that simple. We have to do that in phases and very carefully monitor the outcome. This is why the automatic update is not shown automatically to everyone when release is announced. In the blog post about the release it is said that until the update is pushed to everybody, you need to install the update from the link manually. There is always a chance some things might go wrong even with the most thorough testing (version 10.3 had been tested for 2 months). For example now it seems there is a bug in macOS 15.4, that has just been released as well (almost at the same moment as 10.3), that may cause instability issues with version 10.3. It would be irresponsible to push that version to everybody. Currently we are evaluating that particular issue.