AE doesn't allow e-mails exchanged between agents and members...they can request it online or over the phone.
Why in some cases you can't call us or request mileage online? Because some airports can't do the crediting, they are not using the same system. There's quite a few Caribbean destinations and some airports in the US.
As for AC crediting it's usually quick if your flight has been taken more than 2 weeks after you send the request (online or fax or phone).