Merge pull request #5852 from matrix-org/t3chguy/fix/15777

Switch to a spec conforming email validation Regexp

src/email.ts

@@ -14,7 +14,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-const EMAIL_ADDRESS_REGEX = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,}$/i;
+// Regexp based on Simpler Version from https://gist.github.com/gregseth/5582254 - matches RFC2822
+const EMAIL_ADDRESS_REGEX = new RegExp(
+    "^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*" + // localpart
+    "@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$", "i");
 
 export function looksValid(email: string): boolean {
     return EMAIL_ADDRESS_REGEX.test(email);