How to configure SmarterMail to reduce incoming and outgoing spam emails

SmarterMail can be configured to reduce Incoming and Outgoing spam emails upto 90-95% with its pre-installed anti-spam options. Following are some of the recommendations to prevent Incoming and Outgoing spam emails:

Enable SmarterMail Greylisting Feature

SmarterMail supports Greylisting Feature to defend email users against incoming spams. The Greylisting technique is based on the fact that mail servers that send automated spams are usually not legit mail servers. If the sender mail server and mail both are legit, originating mail server will try again after a delay, and if sufficient time has elapsed an email will be accepted.

Using this Greylisting technique, when an email being received through non-white listed or otherwise previously unknown sender, its sender, recipient, and sending server's IP address will be logged and then the message will be refused by Greylisting.

How to Setup Greylisting?

Login to your SmarteMail interface as a primary admin and perform below mentioned steps:

• 1. Go to Security >> Greylisting >> Options
  2. SELECT Enable Greylisting
  3. UNSELECT Enable users to override Greylisting
  4. SET the BLOCK PERIOD
  5. SET the PASS PERIOD
  6. SET the RECORD EXPIRATION

Setup SPF (Sender Policy Framework)

We always encourage our Windows VPS customers to create a Sender Policy Framework(SPF) record for their domain(s). An SPF is a DNS record that identifies which mail servers are permitted to send emails on behalf of your domain. It prevents outgoing spam messages and “Spoofing” (forged email appears to be coming from your domain). SPF prevent spammers from forging messages that impersonate your domain as the sender. It verifies that incoming mail from a domain comes from a host authorized by that domain's administrators or not.

The list of authorized sending hosts for a domain is published in the Domain Name System (DNS) records for that domain in the form of a specially formatted TXT record. Please be noted that if your domain does not have an SPF record, some recipient domains may reject messages from your users because they cannot validate that the messages are coming from an authorized mail server. To enabling SPF Authentication, refer to the following steps:

Once you login SmarterMail interface using ‘admin’ user, navigate to,

• Security >> Antispam Administration (in the navigation panel) >> Spam Checks > Enable SPF

After enabling SPF authentication, you will have to generate SPF record from any SPF record Wizard and set them into your Domain’s DNS zone where your domain is hosted. Here you can see the examples of generated SPF records. An SPF record is added to your domain's DNS zone file as a TXT record.

'a' Specifies all IPs in the DNS A record. => Example: "v=spf1 a:yourdomain.com -all"

'mx' Specifies all A records for each host's MX record. => Example: "v=spf1 mx mx:yourdomain.com -all"

The all mechanism usually goes at the end of the SPF record; and it is prefixed with a qualifier as shown in table. In case if you need help setting up your SPF record, contact us anytime for further assistance.

Create DomainKeys (DKIM)

DomainKeys (DKIM) is an e-mail authentication system that embeds digital signatures in email messages which can be verified using public keys published in the DNS. DKIM ensures that emails are being received from the listed senders and the messages have not been modified during its transit. To enable DKIM, follow these steps:

Once you login SmarterMail interface using ‘admin’ user, navigate to,

• Security >> Antispam Administration (in the navigation panel) >> Spam Checks >> Enable DomainKeys

Once you enable DKIM, you will have to create DomainKey for your domain and add into your mail server (SmarterMail server). Here are the steps to set up DKIM/DomainKeys in SmarterMail:

• Log into SmarterMail as the domain administrator/admin.
• Click the Settings icon.
  
  
  
  
• Expand the Domain Settings and Advanced Settings folders in the navigation pane.
• Click Mail Signing.
• Click the Options tab and select the Enable DKIM Signing checkbox for DKIM or Enable Domain Key check box.
• Click the Certificate tab. In the Selector field, enter yourdomain name.
• Click Generate Key in the content pane toolbar.

The TXT Record Name and TXT Record Value fields will populate. You will need to add this TXT record in DNS Zone of a domain with this name and value.

Setup Reverse DNS (rDNS)/PTR Record 

Reverse DNS is the determination of a domain name associated with a given IP address using the Domain Name System (DNS) of the Internet. We can simply say that it is opposite of
forward DNS which maps domain names to IP addresses. If you are an administrator, you can setup rDNS by adding a new PTR record and an IP address. For the Canonical Hostname, enter the domain name you’d like the IP address to resolve to, e.g., mail.yourdomain.com. When you do not have access to perform this, you should contact your hosting provider or ISP for this. All AccuWebHosting VPS customers can submit a ticket to setup rDNS record.

SmarterMail Spam Filtering Options

You can also set up spam filtering in SmarterMail at a user level. Please refer our knowledge-base article for more information. If you want to override any spam filtering settings for particular account, you sholud refer an article here.

Set Strong Passwords

We always recommend our customers to set strong passwords for their email accounts. A password must be minimum of 8 characters in length with at least ONE UPPERCASE LETTER, 1 NUMBER and 1 SPECIAL CHARACTER. The longer the password, the more secure your mailbox is. To check your password requirement settings, navigate to following path in your SmarteMail interface and modify your password settings as necessary.

• Security >> Advanced Settings >> Password Requirements

Don't Reply to Phishing Emails

Make sure you or your users don't respond to any phishing emails. For recommended spam settings and advance anti-spam administration, you can refer following URLs:

https://portal.smartertools.com/kb/a2734/recommended-spam-settings.aspx

http://help.smartertools.com/SmarterMail/v10/Default.aspx?qq=%2fSmarterMail%2fv10%2fTopics%2fSystemAdmin%2fSecurity%2fAntiSpam.aspx

Note - It is always recommended to email checker service to clean your email list before sending an email campaign.