I can use the sendMail action but the sendMailWithAttachment does not work, neither do other attachment actions. The all report the same thing in the logs:
2023-01-02 21:40:44.092 [ERROR] [internal.handler.ScriptActionHandler] - Script execution of rule with UID ‘test-1’ failed: ‘sendMailWithAttachment’ is not a member of ‘org.openhab.core.thing.binding.ThingActions’; line 25, column 2, length 133 in test
In DSL rules, use “sendMail” Even with attachments. This was probably not renamed for backward compatibility.
I believe the documentation is not clear about that.
Looking at the code, I expect only methods sendMail and sendHtmlMail but with different variants to be able to attach one attachment or a list.
A mapping table should be added in the documentation, even if it is very simple.
For your information, the enhancement is now merged. In DSL rules, you can both syntaxes (method names) but now the syntax with method names from README will work.