Exchange Mail Quota settings must not restrict receiving mail.

From MS Exchange 2013 Mailbox Server Security Technical Implementation Guide

Associated with: CCI-001094

SV-84625r1_rule Exchange Mail Quota settings must not restrict receiving mail.

Vulnerability discussion

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.

Check content

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

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.

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.