* GH-8577: Deprecate ImapIdleCA.sendingTaskExecutor
Fixes https://github.com/spring-projects/spring-integration/issues/8577
When we process mail messages in async manner, it is possible that we end up
in a race condition situation where the next idle cycle closes the folder.
It is possible to reopen the folder, but feels better to block the current idle
cycle until we are done with the message and therefore keep folder opened.
* Deprecate `ImapIdleChannelAdapter.sendingTaskExecutor` in favor of an `ExecutorChannel`
as an output for this channel adapter or similar async hand-off downstream.
* Make a default one as a `SyncTaskExecutor` to make a sense of this deprecation
* Fix language in docs
Co-authored-by: Gary Russell <grussell@vmware.com>
---------
Co-authored-by: Gary Russell <grussell@vmware.com>
9ffc2db9f5