With each release of Exim, three files are relevant for understanding changes. We link here to the current versions in Git, but all come as part of the release tarballs.

• README.UPDATING provides warnings of backwards incompatibilities which should be carefully understood before updating.

• NewStuff file describes new features with each version of Exim.

• ChangeLog file describes all non-trivial changes, including reworkings, new features, bug fixes, and security fixes.

The README.UPDATING file can be found in the top-level directory of the releases; the others can be found in the doc/ sub-directory.