Managing email flows - Amazon WorkMail

Managing email flows

Set up email flow rules to handle email flows based on email addresses or domains. Email flow rules are based on both the sender's and recipient's email addresses or domains.

To create an email flow rule, specify a rule action to apply to an email when a specified pattern is matched.

Inbound email rule actions

Inbound email flow rules help prevent undesirable email from reaching your users' mailboxes. You can use these rules with an AWS Lambda function to process incoming email before it is delivered to your users' mailboxes. For more information about using Lambda with Amazon WorkMail, see Configuring Lambda for Amazon WorkMail. For more information about Lambda, see the AWS Lambda Developer Guide.

Inbound email flow rules, also called rule actions, automatically apply to all email messages sent to anyone inside of the Amazon WorkMail organization. This differs from email rules for individual mailboxes.

The following rule actions define how inbound email is handled. For each rule, you specify sender and recipient patterns together with one of the following actions.

Action Description

Drop email

The email message is ignored. It is not delivered, and the sender is not notified of the non-delivery.

Send bounce response

The email message is not delivered, and the sender is notified of the non-delivery in a bounce message.

Deliver to junk folder

The email message is delivered to users' spam or junk folders, even if it is not originally identified as spam by the Amazon WorkMail spam detection system.

Default

The email message is delivered after being checked by the Amazon WorkMail spam detection system. Spam email is delivered to the junk folder. All other email messges are delivered to the inbox.

Other email flow rules with a less specific sender pattern are ignored. To add exceptions to domain-based email flow rules, configure the Default action with a more specific sender pattern. For more information, see Sender and recipient patterns.

Never deliver to junk folder

The email message is always delivered to users' inboxes, even if it is identified as spam by the Amazon WorkMail spam detection system.

Important

By not using the default spam detection system, you could expose your users to high-risk content from the addresses that you specify.

Run Lambda

Passes the email message to a Lambda function for processing before or while it is delivered to users' inboxes.

Note

Inbound email is first delivered to Amazon Simple Email Service (Amazon SES) and then to Amazon WorkMail. If Amazon SES blocks an incoming email message, then rule actions won't apply. For example, Amazon SES blocks an email message when a known virus is detected or because of explicit IP filtering rules. Specifying a rule action, such as Default, Deliver to junk folder, or Never deliver to junk folder has no effect.

Outbound email rule actions

Outbound email flow rules can be used to direct email messages via SMTP gateways, or to block senders from sending email messages to specified recipients. For more information about SMTP gateways, see Configuring SMTP gateways.

Outbound email flow rules can also be used to pass the email message to an AWS Lambda function for processing after the email is sent. For more information about using Lambda with Amazon WorkMail, see Configuring Lambda for Amazon WorkMail. For more information about Lambda, see the AWS Lambda Developer Guide.

The following rule actions define how outbound email is handled. For each rule, you specify sender and recipient patterns together with one of the following actions.

Action Description

Default

The email message is sent via the normal flow.

Drop email

The email message is dropped. It is not sent, and the sender is not notified.

Send bounce response

The email message is not sent, and the sender is notified with a message that the administrator blocked the email message.

Route to SMTP gateway

The email message is sent via a configured SMTP gateway.

Run Lambda

Passes the email message to a Lambda function for processing before or while the email message is sent.

Sender and recipient patterns

An email flow rule can apply to a specific email address, or all email addresses under a specific domain or set of domains. You define a pattern to determine the email addresses that a rule applies to.

Both sender and recipient patterns take one of the following forms:

  • An email address matches a single email address; for example:

    mailbox@example.com
  • A domain name matches all email addresses under that domain; for example:

    example.com
  • A wildcard domain matches all email addresses under that domain and all of its subdomains. A wildcard appears only at the front of a domain; for example:

    *.example.com
  • Star matches any email addresses under any domain.

    *
Note

The + symbol is not valid inside of sender or recipient patterns.

Multiple patterns can be specified for one rule. For more information, see Inbound email rule actions and Outbound email rule actions.

Inbound email flow rules are applied if either the Sender or From header in an inbound email message matches any patterns. If present, the Sender address is matched first. The From address is matched if there is no Sender header or if the Sender header doesn't match any rule. If there are multiple recipients for the email message that match different rules, each rule applies for the matched recipients.

Outbound email flow rules are applied if the recipient and either the Sender or From header in an outbound email message matches any patterns. If there are multiple recipients for the email message that match different rules, each rule applies for the matched recipients.

If multiple rules match, the action of the most specific rule is applied. An example is when a rule for a specific email address takes precedence over a rule for an entire domain. If multiple rules have the same specificity, the most restrictive action is applied. An example is when a Drop action takes precedence over a Bounce action. The order of precedence for actions is the same as the order in which they are listed in Inbound email rule actions and Outbound email rule actions.

Note

Take care when creating rules with overlapping sender patterns with Drop or Bounce actions. Unexpected precedence ordering could result in many inbound email messages not being delivered.