As expected some users report "mail server problems" as they may be unaware of mail server IP changes and are victims of DNS propagation delay. To find out if your domain is resolving to a new server IP please follow these directions:
Open windows command prompt and type in "nslookup mail.ihostasp.net". You can substitute mail.ihostasp.net with mail.your_domain.com.
If you see following in the output, this means your PC is resolving correctly to a new mail server IP address.
Non-authoritative answer:
Name: mail.ihostasp.net
Address: 209.190.184.120
However if the nslookup returns following, your PC still has not updated its DNS cache or your Internet service provider DNS servers have not refreshed its records.
Non-authoritative answer:
Name: mail.ihostasp.net
Address: 65.91.41.220
To access web mail while DNS is propagating, you can use following URL.
http://209.190.184.120
The e-mail is functional, messages are being sent and received. DNS should fully propagate with in next 24 hours and you will be able to access mail server using a host name.