Spam Filtering

SmarterMail includes a variety of antispam measures that will help keep a user's inbox free of unwanted mail. When a message arrives, the enabled spam checks give it a score that places it in a low, medium, or high probability category, and an Action is taken based on that category. In the Spam Filtering section, users can review/configure those actions, along with their own trusted and blocked senders.

In most cases, a system or domain administrator has already configured the filtering options for spam messages on your domain. However, if they allow it, you can override those settings to select your own options for filtering out potentially unwanted email.

Options

• Override spam settings - Enable this setting to customize the way spam is handled and to override the settings created by your administrator. If this option is disabled, the policy that applies to you is displayed — greyed out, with a "Source: Domain Policy" or "Source: System Policy" watermark showing where it comes from — and cannot be edited. (If your administrator hasn't allowed overrides, this toggle doesn't appear at all.)

When you override the spam options set by your administrator, the Options card displays a card for each spam level: Low, Medium, and High Probability of Being Spam. Click a card to choose the action you wish to have taken for that level:

• No Action - The message is delivered normally.
• Delete Message - The message is deleted outright and is unrecoverable. Best reserved for the High probability level, if used at all.
• Move to Junk Email Folder - The message is delivered to your Junk Email folder, where it can still be reviewed and rescued.
• Add Text to Subject - The message is delivered normally, but with text you specify added to the subject line. When you choose this action, a "Text to Add" box appears — e.g., entering "[Possible Spam]" tags each suspect message so you can eyeball or filter them easily.

Trusted Senders

Users can add specific email addresses (such as jsmith@example.com) or domains (such as example.com) that will be exempted from general spam filtering. This lets the system know that these messages come from a trusted source and can prevent mail from friends, business associates, and/or mailing lists from being blocked or sent to the Junk Email folder. By default, every contact in a user's Contacts list is considered a trusted sender and bypasses spam filtering — a banner on the card reminds you of this. Adding domains and/or email addresses also impacts the "Verification Score" of a sender — the shield that is displayed alongside a sender's address when viewing messages in webmail.

However, if the system administrator has enabled SPF, DKIM, and/or DMARC (all of which are strongly recommended), SmarterMail will run those checks on ALL emails, including those from trusted senders, whitelisted IP addresses, and IP bypasses. This "trust but verify" approach is important because anyone can write any return path that they want when sending a message. Therefore, this extra layer of protection helps prevent spammers from flooding users with hundreds of messages that aren't truly from a trusted sender. If an SPF, DKIM, or DMARC check fails on an incoming message, the "trusted sender" is no longer trusted by SmarterMail, and the weights of all enabled spam checks will be applied to that message.

If the trusted sender status of an email was bypassed due to a failed SPF, DKIM, or DMARC check, the TotalSpamWeight line in the email header will specify the check(s) that failed, and why. Additional information about SPF, DKIM, and DMARC status can also be found in the header.

The Trusted Senders card has up to three editable areas. Users simply click the pencil icon to add the following, one item per line:

• Trusted Domains - Full domain names (e.g., example.com) to add as "Trusted". Trusting a domain trusts every address at that domain, which is handy for a business partner whose whole staff emails you.
• Trusted Email Addresses - Full email addresses (e.g., jsmith@example.com) to add as "Trusted".
• Bypass Spam Filtering for Unverified Senders - This will only be displayed if the domain administrator has enabled the setting. Full email addresses the user wants to exempt from ALL spam checks, including the SPF, DKIM, and DMARC checks described above. Because this removes the "verify" from "trust but verify", it should only be used for senders whose mail repeatedly fails authentication through no fault of their own.

Blocked Senders

Users can add specific accounts to their Blocked Senders list. For example, if you receive a message from dan@im-a-spammer.com, you can use "Block Sender" from the Actions menu (or right-click context menu) in the message view. When you do this, any future message from that specific sender will have whatever Action is set on the Blocked Senders card applied. This allows users to have a bit more granular control over senders that escape whatever spam filtering the system administrator has set up.

The Blocked Sender Action determines what happens to mail from blocked senders:

• None - Nothing happens to the messages from Blocked Senders.
• Move To Junk Email Folder - Messages are moved to the Junk Email folder, then handled however items in that folder are handled (e.g., auto-clean rules).
• Move To Deleted Items Folder - Messages are moved to the Deleted Items folder, then handled by whatever rules apply for that folder (e.g., auto-clean rules).
• Delete - The messages are flat out deleted and, therefore, unrecoverable. A warning banner appears on the card when this action is selected, as a reminder of exactly that.

The card contains two lists, each edited by clicking its pencil icon:

• Blocked Senders - Full email addresses to block. Any address you've blocked from the message view appears here, and addresses can also be entered manually, one per line.
• Blocked Domains - Full domain names to block. Use this when unwanted mail keeps arriving from a rotating set of addresses at the same domain — blocking the domain catches them all.