Admin | Set up mail flow rules

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Admin | Set up mail flow rules

5 min read

Available with these plans:

Starter

Basic

Pro

Enterprise

To upgrade your Lark Plan or for more information, contact Support or your Customer Success Manager. The Lark Basic plan supports only specific countries and regions.

I. Intro

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Availability: This feature is in beta.

Who can perform these steps: Primary administrators or administrators with "Mail" permission.

As an administrator, you can create email flow rules in the Lark Admin Console for incoming and outgoing emails. For example, you can create a rule to reject emails or change recipients based on set conditions.

II. Steps

Set up rule name and scope

Open the Lark Admin Console and click Product Settings > Mail > Security and Anti-spam > Mail Flow > Create Rules.

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Fill in the rule name, description, and the scope of the rule. Then, click Next.

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Notice:

If you select Entire organization, the rule will apply to all members.

If you select Set range, the rule only applies to selected members, departments, public mailboxes, mailing lists, or user groups (including dynamic user groups).

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Set rules for mail types

You can set rules for emails sent or received internally or externally.

Under When the selected situations occur, select the email type to which you want to apply this rule.

Note:

"Internal messages" refers to emails sent and received from an organization's active domain or subdomain.

A mail flow rule can only be triggered if at least one of the recipients or the sender is within the current mail flow app scope. If only the Cc or Bcc recipients are within the email flow app scope, the rule will not be triggered.

The recipients and sender must be able to send and receive messages normally for the email flow rule to be triggered. When the original sending or receiving addresses are unavailable, such as when a domain is suspended or deleted, the email flow rule cannot be triggered.

Add conditions

Email content will be searched based on these conditions. If an email is found to contain specified content, then the corresponding action will be automatically carried out.

Select whether the email needs to meet one or all conditions. If you select any of the following conditions are met, the corresponding action will be triggered if the content of an email meets any of the conditions.

Click Add Condition, select the part of the email to search and the matching method, then enter keywords. You can add up to 10 conditions for a single rule.

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Note: Please refer to the tables below to learn more about different locations in an email as well as a description of matching methods:

Match location

Location	Description
Message body	The main body of an email. Does not include attachments.
Email subject	The email subject that appears in the email header.
Sender	The sender appears in the email header and the email envelope.
Recipient, Cc, or Bcc	The recipient shown in the email's "Sender," "CC," or "BCC" sections. Note: Only detects email addresses, not including account names. For example: To: Joe Bloggs <Joebloggs@example.com> CC: Fred Bloggs <fbloggs@example.com> BCC: Jane Doe <Jdoe@example.com> Will only detect: Joebloggs@example.com, fbloggs@example.com, and Jdoe@example.com

Matching method

Matching method	Description
contains	Searches locations for content that contains specific text or email addresses.
does not contain	Searches locations for content that does not contain specific text or email addresses.
is equal to	Searches locations for content that is an exact match for specific text or email addresses. Only 1 keyword or email address can be entered.
matches regular expression	Searches locations for content that matches a specific regular expression. You can enter up to 128 characters for a single regular expression.

Specific content matches

Specific content	Description
Sender IP within the following range	Sender IP refers to the server IP address of the sent email. This will only carry out sender IP matching on the received email.
Email content contains sensitive information	Searches the text content of the email subject and message body for matching selected sensitive information (such as an ID number or phone number).

Actions taken when rules are triggered

Reject emails

You can reject an email before the recipient receives it.

In the drop-down menu below The following actions will be carried out (Then do this), select Reject the message.

You can set a custom message to notify the sender of the reason their email was rejected. Lark will not apply any other flow rules after this action is taken.

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Quarantine emails

You can move emails into quarantine so that administrators can review them. Administrators can then decide to either approve or reject them.

In the drop-down menu below The following actions will be carried out (Then do this), select Move to quarantine.

If you need the sender to be notified when the email is quarantined, select Notice the sender when message is moved to quarantine.

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Modify emails

You can redirect emails, add more recipients, add email subject prefixes, or add headers when specified rules are triggered.

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Modification type	Description	Specific method
Redirect	Bypasses the original recipient and sends the email to a new recipient.	Redirect to others: You can choose to redirect to organization members, public mailboxes, mailing lists, or any email address. You can also redirect to multiple people. You can add up to 50 organization members, public mailboxes, or mailing lists, as well as up to 50 external email addresses. Modify recipient's domain name: Only modifies the domain name of the recipient's email address, for example, "example.com." The user name will remain unchanged. Please enter the domain that should appear following the modification. Example: An email's original recipient is jone@abc.com. By modifying the recipient's domain, the email will be redirected to jone@example.com. Note: When triggering a redirection to other recipients, all recipients displayed in the "To", "Cc", and “Bcc” sections will not receive the email. When triggering a change to the recipient's domain, the domain of all recipients displayed in the "To", "Cc", and “Bcc” sections will be modified. When triggering a redirection to other recipients or changing the recipient's domain, the email will be delivered to the modified recipients, but the recipient information displayed in the email will not change. For example, if the original recipient is A, and B is cc'd, triggering a redirection to C. C will receive the email, but A and B will not. However, the email will still display A as the recipient and B as the Cc.
Add more recipients	You can send an email to additional recipients.	Select whether the type of additional recipient will be an ordinary recipient, CC, or BCC. You can add up to 50 organization members, public mailboxes, or mailing lists, as well as up to 50 external email addresses for each type.
Add a prefix to the email subject	Add custom text to the start of an email subject.	Select this option and enter the custom text. Example: You can enter "[External]" in emails that originate externally. If this rule is triggered by an email with the subject "Event Invite," the recipient will see the following subject: "[External] Event Invite."
Bypass spam filters	Emails sent to you will avoid spam filters even if the system detects them as spam.	Select Bypass spam filters. Note: This action will not affect: Sent emails Emails received by mailing lists Emails that trigger anti-phishing and spoofing policies Emails that trigger custom "Move to spam" rules
Add customized header	Add customized headers for emails that match set conditions.	Enter headers and header values separately.

Set rule priorities

Rule priority determines the order in which Lark carries out rules. For example, Lark carries out rules set as priority 0 first.

Click More options to show priority settings.

You can set the rule priority of all current rules. For example, if there are currently three rules, they will be carried out in order of priority from 0 to 2.

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Note: When a rule condition is triggered and the action taken is Reject the message or Move to quarantine, the action is carried out immediately and no other actions are carried out.

Click Create for the flow rule to take effect.

III. FAQs

What is the maximum number of mail flow rules?

An organization can have up to 100 mail flow rules.

If an email triggers both "Add more recipients" and "Redirect" rules, will the recipient who was added receive the email?

Yes.