Although we have considerable control over the look and feel of our communities through the custom theme settings, there is virtually no control over the look and feel of the notification email messages that are sent from them. There is very limited opportunity to adjust the content of the messages using the Languages & Strings fragments, but we cannot adjust the order in which they are combined.
The only branding we can do without assistance from support is by using the banner graphic.
We would very much like to be able to edit the templates for the email notifications that our communities produce. The data values that are available to be plugged into those messages could be provided as mail-merge fields (or just the numbered parameters used in the Languages & Strings messages). Then we could control the styling that is applied to the email messages.