Checklist of recommended best practices for your office email server

Having a latest hardware with leased internet connectivity and a feature rich email client are not the only requirements you need to setup your office email server. Unless you can send mails to your clients, partners and associates across the globe, your mail server is of no practical use. It is the trustworthiness of your mail server over the Internet that is standing between you and the recipient.

To be a trusted E-mail sender we need to follow the best practices which are highlighted below:

1.  Messages from IP (No Domain)

Messages should be from a domain and not from any IP Address. e.g. user@nulldomain.com is a valid sender, whereas user@null192.168.0.18 is an invalid sender and thus the mail will be rejected.

2.  Mail Servers on Dynamic/Dial-up Addresses

The sender server IP Address must not be a dynamic IP. Normally all IP addresses should have a correct reverse DNS, and especially email servers. Most Anti-Spam tools will reject email from places whose reverse DNS looks not to belong to an email server, but more likely to be a home or office dynamic address. If you are running an email server, make sure the Reverse DNS of the IP address reflects your domain, e.g.  ‘gateway.yourdomain.com’ or ‘mail.yourdomain.com’.

3.  Valid FROM domain

The FROM address is important as it is the address that would be used if problems were encountered delivering the message, so if the address can’t be responded to, the E-mail cannot be accepted from that address either.

e.g. user@nullyourdomain.com is an accepted sender but the following bad examples will get rejected:

user@localhost
user@null192.168.1.200
user@nullmyfakedomain.not

4.  The sender server must identify itself and the identification must be Valid (Valid HELO)

Most email servers and anti-spam tools will not allow mails to be received unless the above protocol is in place. This practice does not supply enough information to safely identify the server and responsible party, if a problem email is received. And almost every mail server offers this capability. This is a simple rule which just insists that the HELO (or EHLO) is sent with every email connection and it is properly formatted.

In order to ensure that messages are not stopped by this check, make sure the HELO is a FQDN.The HELO string sent should in the style of:

HELO mta1.mycompany.com

The following bad example(s) will get rejected:

HELO
HELO localhost
HELO hostnameonly
HELO 192.168.1.1 (just an IP)

If you are the one who is not receiving emails or are unable to send mail to some of your recipients, you may ask them to check if they really follow these practices.

At Diadem Technologies, we provide secure and reliable hosted email solutions on shared, dedicated and virtual servers. With over 10,000 hosted mailboxes and a decade of expertise, we have the right solution for your needs. Please visit our website or drop us a line for more details.

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