HOWTO: Resolve domain names with a host file when using Zetafax SMTP Gateway
This Zetafax technical note applies to:
- Zetafax 2012 and later
- Zetafax SMTP Gateway
Within the configuration screen for Zetafax SMTP Server you can specify the IP address of a DNS server to resolve domains when passing emails to your mail server. Similarly for outbound faxes where you would address emails to a fax domain e.g. fax.contoso.com, a DNS entry can also be created to achieve this.
If you do not wish to make modifications on your DNS server you can optionally configure the host file on the Zetafax Server and/or email server.
Host file warning
WARNING: Modifying the host file can cause problems that may affect domain name resolution and network traffic. Equisys cannot guarantee that problems resulting from the incorrect use of the host file can be solved. We advise to back up the host file before any modifications are made.
For inbound faxes and notification emails
1. On the Zetafax SMTP Server, go to Start -> Programs -> Zetafax SMTP Server -> Zetafax SMTP Server Configuration.
2. Ensure the IP address for setting ‘DNS Server’ is left blank. Zetafax SMTP Server will then revert to looking at the Windows host file to resolve domain names.
3. Go to C:\Windows\System32\Drivers\etc. Make a backup of the file named ‘hosts’.
4. Open the hosts file in Notepad or a similar plain text editor (you may require elevated admin privileges to modify this file).
5. On a new line, add an entry using the following format:
< ip address of mail server> < domain name of email/fax recipient>
6. Save the file.
The configuration is complete and Zetafax Server will now be able to relay inbound email to your mail server.
For outbound faxes
1. On the email server go to C:\Windows\System32\Drivers\etc or equivalent folder if the mail server is running on a different operating system. Make a backup of the file named ‘hosts’.
2. Open the hosts file in Notepad or similar plain text editor (you may require elevated admin privileges to modify this file).
3. On a new line, add an entry using the following format:
< ip address of Zetafax SMTP Server> < fax domain>
4. Save the file.
Test an outbound fax by addressing an email to < fax number> @fax.contoso.com
Last updated: 18th December 2013 (JW/MW)