Exchange Mail Quota settings must not restrict receiving mail.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-70003	EX13-MB-000160	SV-84625r1_rule		Low

Description
Mail quota settings control the maximum sizes of a user’s mailbox and the system’s response if these limits are exceeded. Mailbox data that is not monitored against a quota increases the risk of mail loss due to filled disk space, which can also render the system unavailable. There are multiple controls, which supply graduated levels of opportunity to respond before risking email service loss. This control prohibits the user from sending an email when the mailbox limit reaches the prohibit send quota value. Note: Best practice for this setting is to prohibit the user from sending email when the mailbox reaches 90 percent of capacity.

Description

Mail quota settings control the maximum sizes of a user’s mailbox and the system’s response if these limits are exceeded. Mailbox data that is not monitored against a quota increases the risk of mail loss due to filled disk space, which can also render the system unavailable. There are multiple controls, which supply graduated levels of opportunity to respond before risking email service loss. This control prohibits the user from sending an email when the mailbox limit reaches the prohibit send quota value. Note: Best practice for this setting is to prohibit the user from sending email when the mailbox reaches 90 percent of capacity.

STIG	Date
MS Exchange 2013 Mailbox Server Security Technical Implementation Guide	2019-12-23

Details

Check Text ( C-70477r1_chk )
Review the Email Domain Security Plan (EDSP). Determine the value for Prohibit Send Quota Limit. Open the Exchange Management Shell and enter the following command: Get-MailboxDatabase \| Select Name, Identity, ProhibitSendQuota If the value of ProhibitSendQuota is not set to the site's Prohibit Send Quota Limit, this is a finding.

Fix Text (F-76239r1_fix)
Update the EDSP. Open the Exchange Management Shell and enter the following command: Set-MailboxDatabase -Identity <'IdentityName'> -ProhibitSendQuota <'QuotaLimit'> Note: The and values must be in quotes.