diff --git a/lam/lib/account.inc b/lam/lib/account.inc
index 80b7b1c1..90dc3d2a 100644
--- a/lam/lib/account.inc
+++ b/lam/lib/account.inc
@@ -518,7 +518,7 @@ function get_preg($argument, $regexp) {
 					$pregexpr = '/^[[:digit:]]+(\\.[[:digit:]]+)?$/';
 					break;
 		case "UNC":			// UNC Path, e.g. \\server\share\folder\...
-					$pregexpr = '/^((([\\\][\\\])|(%))([a-zA-Z0-9%\\.-])+)([\\\]([[:alnum:]%\\.\\$\\ \\_-])+)+$/u';
+					$pregexpr = '/^((([\\\][\\\])|(%))([a-zA-Z0-9@%\\.-])+)([\\\]([[:alnum:]@%\\.\\$\\ \\_-])+)+$/u';
 					break;
 		case "logonscript":	// path to login-script. normal unix file
 					$pregexpr = '/^(([\/\\\])*([[:alnum:]%\\.\\ \\$\\_-])+([\/\\\]([[:alnum:]%\\.\\ \\$\\_-])+)*((\\.bat)|(\\.cmd)|(\\.exe)|(\\.vbs)))*$/u';