Originally Posted by DallasBill
In my 20 years of IT and email, that's the first I have heard of it!
Could you please point to an RFC or standard for all our edification & enlightenment!
Interestingly enough, RFC 822/2822 are quite liberal when it comes to defining the e-mail address format.
As per RFC 2822, "3.4. Address Specification" and the definitions contained in "3.2.4. Atom", valid characters for an e-mail address are:
- A-Z
- a-z
- 0-9
- ! # $ % & ' * + - / = ? ^ _ ` { | } ~
- .
But that's just in theory. In practice, I wouldn't use anything other than "-", "_", and "."