The Sender Verification Shield is a way to help users understand the "validity" of a sender's email address. From an antispam standpoint, it uses SPF, DKIM, and DMARC to verify the sender's email server and domain.
However, many larger installations of SmarterMail make use of incoming gateways to help facilitate the flow of incoming messages, and these gateways can muddy Sender Verification results.
To remedy that, a system administrator has two (2) options: either turn off Sender verification entirely, or add the IP(s) of any incoming gateways to the IP Bypass list.
Turn On/Off Sender Verification
To turn off Sender Verification, do the following:
- Log in as the system administrator
- Select the Manage tab.
- Select Domain Defaults.
- On the Email card, toggle "Enable Sender Verification" to either enable or disable it.
- Save that change.
It's also possible to turn Sender Verification on or off on individual domains. Simply edit the domain, and on the Options tab, the Sender Verification setting is on the Email card.
Add Gateway IP(s) to IP Bypass
To continue using Sender Verification with incoming gateways, you need to add the gateway IP(s) to the IP Bypass list:
- Log in as the system administrator.
- Select the Settings tab.
- Select Security.
- Select the Whitelist tab.
- Click the New button.
- Set the Source to IP Address
- Add the IP addresses (single, a range, or a CIDR block) you want to bypass.
- Toggle on Bypass IP for Spam Checks.
- Click Save.
Once done, SmarterMail will run through the Received: values in message headers and simply ignore any IPs that are being bypassed and only use those IPs that are NOT bypassed for Sender Verification checks.