If you send a mass email or alert (maybe conversations as well) in 1.5 up to beta 4, the placeholders ({name}, {id}, {email}, etc) may be replaced with information from the incorrect user. This is now fixed for the next release.
If you need to send bulk email/alerts before a fixed version is available, you shouldn't use placeholders.
If you need to send bulk email/alerts before a fixed version is available, you shouldn't use placeholders.