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This PR contains 2 somewhat independent changes, which taken together should make the tests in this package run successfully to completion once again.
The mock smtp server used in the tests was build on a python standard library called
asynccore. This module was deprecated, and finally removed in python 3.12. This is now replaced by theasynciomodule, and theaiosmtpdpackage.The changes in Break attachments into smaller lines #55 broke the tests. Given the passage of time (and the fact that actions history does not go that far back) I'm not sure why we merged it without the tests passing. Maybe it was broken for some other reason? Anyways, another reason to not merge stuff without successful tests, however tempting that may be 😄