A few different places in user registration and login can send email - the "welcome to the site" email, a "verify your email address" email, and the "recover your forgotten password" email. The details of these various emails - the subject, and body - are set through i18n messages, which is convenient for setting correctly translated text, is very clumsy for formatting the email. The sender of the email is also the "system owner" which is usually not correct.
It would be much nicer if these emails were generated from templates or other more flexible means so that they could be multipart messages if desired, and have the sender controlled more easily (e.g., I want them to come from a "support@" address, even though that's not the defined site owner). It would also be nice if all these templates were near each other (i.e., in the same directory) so it's not necessary to go grepping through code to figure out what message key needs to be changed.
