Community Knowledge Base

SMTP Authentication Bypass

SMTP Authentication is a security measure that can be very beneficial in the fight against spam and unauthorized email as it forces the sender to authenticate their username and password before an email is sent through the mail server.

Unfortunately, some applications do not have support for SMTP authentication when sending mail. Most often, these are web sites that have automated mail sending mechanisms. The solution is to add the IP addresses of these servers/sites to SmarterMail's whitelist, and whitelist the IP or IP block for SMTP Authentication Bypass. Adding an IP to the SMTP Auth Bypass whitelist means that the IP address, or IP block, will not be asked to provide an SMTP Authentication login.

To get started, make sure you're logged into SmarterMail as a System Administrator. Then, click the Settings icon and click the Security menu item in the navigation pane. Once the Security page loads, click on the Whitelist tab. A list of whitelisted IP addresses will load in the content pane, if any have been added. In addition, the particular protocol for which the IPs have been whitelisted will be noted. The following options will be available in the content pane toolbar:

  • New - Adds a new IP address or IP Address Range to bypass.
  • Delete - Permanently removes the IP address from the SMTP authentication bypass list.

Adding a Whitelist Entry

Adding an IP address, or an IP address block, is very simple:

  1. First, click the New button.
  2. A modal window opens.
  3. Enter a single IP address or a CIDR block.
  4. Enter a Description for the whitelist. For example, "Internal IPs".
  5. Select one or more protocols/services for which the IP(s) entered will be whitelisted by clicking the toggle switch next the one or more protocols/services.
  6. Save your changes.
  7. Once saved, the new whitelist entry will be displayed in the content pane of the page.

Editing an Entry

Once a IP or IP range has been entered, it's possible to change these. That includes changing the protocols, changing the description or changing a single IP to a CIDR Block. To edit an entry:

  1. Click the IP Address of the entry you want to edit. (Clicking the checkbox simply enables the Delete button.)
  2. A modal will open, displaying the information that was added to the inital whitelist.
  3. Make whatever changes are necessary. Then be sure to click the Save button to save your changes.