Can this happen? I have an Exchange 2003 box that is configure to except mail from my company. Everything works fine, I have just configured the box to except mail from for example mycompany.com and also from myothercompany.com. Everything works fine internally, and my external DNS records point to my email server. When you try to use it externally, mycompany.com gets mail but myothercompany.com doesnt.
Should i be looking into my ASA5510 or my 2801 router?