The manual string building here is obviously a red flag.  We can pass result.address in to the dictionary too but leave the plural macro so that it is only varying over 'n'.  So then the string would look like "new-emails[two]={{ n }} New Emails - {{ accountName }}" or what not.

The other way we could do this is have a separate string that combines the plural-based string and the account name.  So it would be "new-email-display={{count}} - {{ account }}".  The long-term l20n goal is to just have the single string context.  I don't think there are any complicated agreement rules for us here (account type can't vary in interesting ways like gender), so I'd lean towards the single string case.