Print2Email supports using standard email addresses and characters, when sending an email.
The list of the allowed characters before the “@” character (username@domain.com) are the followings:
uppercase and lowercase Latin letters A to Z and a to z;
digits 0 to 9;
special characters !#$%&'*+-/=?^_`{|}~;
dot ., provided that it is not the first or last character unless quoted, and provided also that it does not appear consecutively unless quoted (e.g. John..Doe@example.com is not allowed but "John..Doe"@example.com is allowed);
space and "(),:;<>@[\] characters are allowed with restrictions (they are only allowed inside a quoted string, as described in the paragraph below, and in addition, a backslash or double-quote must be preceded by a backslash);
comments are allowed with parentheses at either end of the local part; e.g. john.smith(comment)@example.com and (comment)john.smith@example.com are both equivalent to john.smith@example.com.
The list of the allowed characters after the “@” character (username@domain.com) are the followings:
uppercase and lowercase Latin letters A to Z and a to z;
digits 0 to 9, provided that top-level domain names are not all-numeric;
hyphen -, provided that it is not the first or last character.