JIRA emails are difficult to translate, because:
- text in the email templates must be converted to UTF-8
- parts of the Subject string are hardcoded
- there is only one global set of templates, so the personal language setting does not affect the email language
- convert text in the templates to UTF-8 or whatever is required, so that emails with international characters can be sent
- put the language ID (default, de_DE etc.) somewhere in the path so that one can have several email template subdirectories or files in the required languages (the templates should ideally live in language_*.jar, but separate directories would be ok too)
- replace all hardcoded text in email processing with accesses to a property file
It is probably not much work but would improve the JIRA look and feel for international customers.