When a mail is sent with cfmail, internally a mail task is created. This task is written as a .tsk file in {web-config}/remote-client/open/00012345.tsk
Inside the .tsk file, the smtp details of the configured mailserver are stored.
There are 2 things wrong with that:
1. the smtp password is stored as plain text
2. the task will never notice a change in configured mailserver settings.

The real-life problem here, is trying to fix wrong mailserver settings on a Lucee server (e.g. changed or wrong password or username)
Even after changing the mailserver settings, and then retrying the mail tasks, they will continue to give an error. Logical, once you find out the mailserver settings are stored within each .tsk file, but untill then, totally confusing and frustrating.

So, my suggestion is, to not save smtp details inb the task files, but instead use the settings given in the lucee administrator.