SUMMARY

If using MailEnable connected to the Internet, it is recommended to have a fixed IP address that is registered under your public DNS. Every domain registered on MailEnable should have mail exchanger (MX) records defined in your DNS to allow other mail servers to look up this IP address.

DETAIL

The simplest way to determine whether other mail servers can locate your server is by sending an email from Hotmail, Gmail, etc. If the email could not be delivered then the delivery failure email back to the sender will indicate why. You can also inspect the SMTP activity log to see whether their server has attempted to deliver the message. 

1. If there is no entry in the activity log, then the remote server could not connect and the issue is likely either network related or a problem with the DNS configuration. For example, a lot of service providers will block inbound port 25 to prevent a mail server being used.

2. If there are entries in the log, the issue is likely to be MailEnable's configuration settings, or the email client used to read the mailbox. The tracking utility can help identify where the received message went, and whether it was blocked. The message tracking utility is found in the administration program.

To check whether your domain has a valid MX record, follow the steps below:

1. Open the Windows Command Prompt
2. Type in "NSLOOKUP", Press ENTER
3. At the">" prompt enter "set type=MX"
4. Yype in the name of your domain

Typically the lookup will outline the MX record as the example below shows:

Note: An MX record is not an absolute requirement, since mail servers will fall back to using the A record for the email domain.

Since this is how other mail servers identify your mail host from the domain name part of a message, the DNS entries have to point to your mail server or you will not receive mail from remote mail hosts. The Diagnostic Utility (under MailEnable Program group and also accessible in the administration program) will show the DNS entries recommended for each domain configured under MailEnable, so can help determine a problem.

MORE INFORMATION

What DNS should be used?: Article ME020043

What DNS records should be created when hosting mail domains?: https://www.mailenable.com/kb/viewarticle.asp?File=me020048.htm

Troubleshooting MX lookup issues: https://www.mailenable.com/kb/viewarticle.asp?File=me020079.htm