Yes it can take a couple of hours for your new DNS records to delegate Pubicly all over the world.
Make sure your port 25 / 110 / ssl ports / 587 <-- Smtp workaround port are all enabled.
Remember your clients may have ISPs that block port 25 as well. So make sure you have 587 enabled for them too while your waiting on your records to delegate.
Most IPgateways have port range enable settings for True Static IP management.
This is what i use to make sure all traffic from the ISP gateway is sent to those servers requesting those ports.
Also this is not requried but you should do it. Call your ISP and tell them to setup your reverse dns for IP 188.8.131.52 to mail.hostingacela.com as a PTR record.
Last edited by Rockdrala; 9th January 2008 at 15:58.