Directories - End User Managed Sender Lists

This article contains information on managing End User Managed Sender Lists in Mimecast, including viewing, adding, modifying, or deleting entries, and importing entries from third-party systems like Postini.

Each user has a list of Managed Senders. These are email addresses and domains they've manually blocked or permitted or were automatically added to their Auto Allow list. An administrator can view, add, modify, or delete these entries.

You can import existing personal entries from third-party systems (e.g., Postini) when migrating to Mimecast. If the option can't be used, create a block senders or permitted senders policy; see Configuring Blocked Senders Policies or Configuring Permitted Senders Policies.

Considerations

• Administrators can manage a user's personal Managed Senders. Such corrections may be necessary when a user has incorrectly created an entry by:
  • Using a digest set to block/permit an external email address. A common example is an end user permitting their own sending address after receiving a spam email. All future spam emails to them are then accepted.
  • Using Mimecast Personal Portal or Mimecast for Outlook to block/permit addresses and/or domain names.
  • Sending a message to an external recipient, which adds the external address to their Auto Allow list.
• Configuring Blocked Senders Policies always supersedes the Permitted Senders policies. This means that messages from a domain or email address that are added to both a Blocked AND Permitted Senders policy are rejected. These policies don't override default virus checks.
• An entry on a user's blocked senders list in Managed Senders, whether it has been added by an Administrator or an End User, is always superseded by a Permitted Senders policy, see Configuring Permitted Senders Policies.
• Permitted/blocked addresses will follow the user to a new primary address, unless the Administrator has set Apply Auto Allow (Original-Recipient Address) on Auto Allow Policies, in which case the permitted/blocked addresses must be re-added for their new primary address.
• Trusted Senders is a feature that is only utilized when Dynamic configuration is set up for the definition, allowing end users to mark a sender as trusted, which modifies how emails are handled. See Attachment Protect Definitions, Attachment Protect Delivery Options.
• For untrusted senders, files are processed through safe transcription, enabling users to release the original if needed. In contrast, when a sender is trusted, attachments go directly to sandboxing without transcription, enhancing security.

End User Managed Sender Lists

You can list a user's Managed Senders, by using the following steps:

1. Log in to the Mimecast Administration Console.
2. Navigate to Email Delivery | Managed Senders.
3. A list of personal entries is displayed, along with a toolbar that allows you to: 

• • Search for an entry by entering the email address/name of the internal user.
  • Block/permit addresses/domains.
  • Delete, view, or add addresses / domains.
  • Export entries.

The View menu can be used to filter by Blocked, Permitted, or Auto Allow entries. Each entry displays the sender/recipient address, along with the policy type:

Policy Type	Icon	Description
Auto		An Auto Allow entry has been created. This is automatically configured when the user sends a message to an external recipient, who is automatically considered a trusted sender. See the Note: An Auto Allow entry is automatically deleted if no messages are sent to the address for 120 days.
Manual		Shows a manual permit entry.
		Shows a manual block entry.
Disabled	-	A small sample of Auto Allow addresses is scanned for spam on a random basis. We may disable the Auto Allow entry and place the message on hold if it is suspected as spam. This doesn't apply to manually created Auto Allow entries, and the Auto Allow rule is re-enabled when the internal user sends an email to the external recipient.
Trusted	or	Displays one of the icons to indicate if the email address has been added to the user's trusted list. See How Does Targeted Threat Protection - Attachment Protect Work?

Blocking, Permitting, and Deleting Entries

You can block, permit, or delete one entry, by using the following steps:

1. Right-click on the entry.
2. Select the Block Sender, Permit Sender, or Delete menu item.

You can block, permit, or delete multiple entries, by using the following steps:

1. Select the Tick Box to the left of the required entries.
2. Select the Block Selected, Permit Selected, or Delete Selected button.

Trusting / Untrusting Entries

See Configuring Attachment Protection Definitions  and Configuring Attachment Protection Policies for further details.

You can trust / untrust users, by using the following steps:

1. Select the Tick Box to the left of the required email addresses.
2. Select either: 

• • Trust Selected.
  • Untrust Selected.

Adding Entries

You can add a Managed Senders entry, by using the following steps:

1. Select the Add button.
2. Select one of the following menu items: 

• • Add Managed Senders
  • Import Managed Senders: See Import Managed Senders.
  • Postini Approved and Blocked Senders: See Postini Approved and Blocked Senders.

Import Managed Senders

The Import Managed Senders menu item allows you to bulk upload multiple entries from a spreadsheet. The spreadsheet must include the columns and values as specified below and should not contain more than 10,000 entries:

Column Heading	Description
sender	The external sender's email address or domain (e.g., [e-mail] OR domain.com).
to	The internal recipient's address (e.g., [e-mail]).
action	Specify either "permit" to bypass spam checks, or "block" to reject the email.
trusted	Specify a "Yes" or "No" value to control whether the user is added to the trusted senders list.

Mimecast only accepts spreadsheets in XLS format, and the layout of the import is critical for the data to be imported correctly.

You can import Managed Senders, by using the following steps:

1. Select Browse to select the spreadsheet.
2. Select Preview Changes to check the spreadsheet structure. A report is generated to indicate if the appropriate fields have been identified correctly.
3. Select Accept Import to start the import process.

Postini Approved and Blocked Senders

A spreadsheet can be used to import user personal permit and block policies. The spreadsheet must include the columns as specified below:

The examples in the table below only apply to the sender address.

Column Heading	Description
# address	The email addresses of the internal users, for which the personal entries should be created. If the email address doesn't exist in the internal domains, the spreadsheet preview generates error notifications. The address must be removed from the import.
approved_senders	A list of email addresses to be added to the personal Permitted Senders entries for the user address listed in the # address column. Multiple addresses must be separated by commas with no spaces.
blocked_senders	A list of email addresses to be added to the personal Blocked Senders entries for the user address listed in the # address column. Multiple addresses must be separated by commas with no spaces.
trusted_senders	A list of email addresses to be added to the personal Trusted Senders entries for the user address listed in the # address column. Multiple addresses must be separated by commas with no spaces.

You can import the addresses, by using the following steps:

1. Select Browse to select the spreadsheet file.
2. Select Preview Changes to check the spreadsheet structure. A report is generated to show if the appropriate fields have been identified correctly.
3. Select Accept Import to start the import process.

The table below provides a number of examples of valid and invalid entries for approved/blocked senders:

Examples	Address Type	Reason for Rejection
@domain.com *@domain.com	Valid Domain	-
[e-mail] [e-mail] ?@domain.com	Valid Email Address	-
domain.com *@	Invalid Domain	Invalid Email Address
name@ name	Invalid Email Address	Invalid Email Address

Export Managed Senders Data

You can only export up to a maximum of 50,000 entries.

You can export data from Managed Senders by using the following steps:

1. Either select individual Managed Senders, by using the checkbox next to them, or select the checkbox next to the top-level Sender heading, to select all items.
2. Click on Export Data.
3. Select details for the export:

• • Columns: Select which column data to include (Sender, To, Policy Type, Trusted, Action).
  • Format: Select .xls or .csv format.
  • Export: Select the Export Option of Send Mail or Download.

5. Click on Export.

API Endpoints

In addition to exporting your Managed Senders data manually, you can also use the following API endpoints:

• Backup: creates a backup snapshot of the customers Mimecast configurations for Managed Senders, Managed URLs, and Profile Groups.
• Export: creates a snapshot of your data, for Managed Senders, Managed URLs, and Profile Groups.
• Bulk delete: deletes Managed Sender entries, based on sender email addresses, or sender domains in addition to optional filtering criteria: Type, Action and Trusted.
• Delete Managed Senders: deletes Managed Sender entries, for a specific internal recipient.
• Delete all Managed Senders: delete all Managed Sender entries that contain internal recipients as senders on the account.