The regex validation breaks certain email delivery services, as they don't simply use mail addresses.
AFAIK, there is no limitation on SMTP usernames, when it comes to authentication.
This template contained several misspellings of "SMTP" and--I'm not entirely sure what the exact cause of this was, as I could not repeat the errors on templates with similar formatting--the RegEx rules would persistently fail for the SMTP boolean settings. I tested across several browsers and encountered the same problem. After wrapping the default values with ' ' they stopped failing the RegEx check. This pull request should be paired with another with similar changes in the GH Pages template.
Zottelchen
Stephen Davis
kgnfth