Understanding Disclaimers


Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Microsoft Exchange Server 2010 includes the ability to add HTML or text disclaimers to e-mail messages that are processed on Hub Transport servers. Disclaimers are typically used to provide legal information, warnings about unknown or unverified e-mail senders, or for other reasons as determined by an organization.

For information about disclaimers in Exchange 2013 and Exchange Online, see Add an Email Disclaimer, Legal Disclaimer, Common Signature, or Email Footer or Header.

Here's an example of an e-mail disclaimer:

IMPORTANT NOTICE: This e-mail message is intended to be received only by persons entitled to receive the confidential information it may contain. E-mail messages to clients of Contoso may contain information that is confidential and legally privileged. Please do not read, copy, forward, or store this message unless you are an intended recipient of it. If you have received this message in error, please forward it to the sender and delete it completely from your computer system.

Another example of a disclaimer is the use of e-mail signatures. Many organizations require that uniform signatures be applied to e-mail. Details such as the sender's name, title, department, company, location, and contact details may be required in signatures. In addition, organizations may require insertion of logos and other branding elements in signatures.

For details about how to create a disclaimer, see Configure a Disclaimer.

Targeting Disclaimers

Exchange 2010 lets you target disclaimers (assign specific disclaimers to specific e-mail messages) based on conditions and exceptions that are defined in transport rules created on Hub Transport servers. Transport rules give you the flexibility to assign specific disclaimers to e-mail messages based on business needs. For example, you could specify different disclaimers for internal and external messages or for messages sent by users in a specific departments or offices. However, when configuring multiple transport rules to apply disclaimers, carefully consider the transport rule conditions you use and avoid applying multiple disclaimers to the same message. For information about the transport rule predicates you can use to target the disclaimer, see Transport Rule Predicates.

Here are examples of business conditions that might require that you use unique disclaimers:

  • Different legal requirements in different countries or regions.

  • Different business or regulatory requirements in different countries or regions.

  • Different languages.

  • Potentially unsafe e-mail messages that are sent to internal users.

Customizing Disclaimers

When you create a disclaimer, you can modify the appearance, position, and behavior of the disclaimer within the e-mail message. You can customize disclaimers by using the following elements:

  • Disclaimer text

  • HTML tags and in-line CSS Styles

  • Using Images in Disclaimers

  • Using Active Directory Attributes in Disclaimers and Personalized Signatures

  • Use of a separator line

  • Placement of the disclaimer

  • Behavior with messages that can't be modified

Disclaimer Text

The disclaimer text is the text that's inserted into a message. Exchange 2010 inserts disclaimers into e-mail messages by using the same message format as the original message. For example, if a message is created in HTML, the disclaimer is added in HTML. If the message is created as plain text, HTML tags are stripped from the disclaimer text before it's added to the plain text message.


In Exchange 2010, the maximum length of disclaimer text is 5,000 characters. This includes any HTML tags and inline Cascading Style Sheets (CSS) styles.

HTML Tags and Inline CSS Styles

Exchange 2010 disclaimer text can include HTML tags. This allows you to create messages with the rich styling functionality available in HTML. Additionally, HTML tags can include inline Cascading Style Sheets (CSS). Messages sent in the HTML format can display the rich disclaimer messages.


You can also configure a transport rule with text-only disclaimers by not using any HTML tags.

Using Images in Disclaimers

In Exchange 2010, you can add images to an HTML disclaimer by using the IMG tag. For example:

<IMG src="http://myserver.mydomain.com/images/companylogo.gif">


Images added by using IMG tags aren't embedded in the message. Images should be located on a Web server that's accessible to the e-mail client.

When determining whether to use IMG tags in a disclaimer, keep in mind that Outlook Web Access, Outlook Web App, and Outlook 2007 and later blocks external Web content (including images) by default. Users may need to perform a specific action if they want to view the blocked external content. Therefore, images added to HTML disclaimers by using the IMG tag may not be visible by default. We recommend that you test disclaimers with IMG tags in the e-mail clients your recipients are likely to use to make sure it meets your requirements.

Using Active Directory Attributes in Disclaimers and Personalized Signatures

In Exchange 2010, you can add Active Directory attributes (such as DisplayName, FirstName, LastName, Department, and Company) to disclaimers and personalized signatures. When a disclaimer rule is triggered, the attribute names are replaced by corresponding values from the sender's Active Directory user account. To use attributes in a disclaimer or personalized signature, you must enclose it in two percent signs (%%). For example, to use the DisplayName attribute, you must use %%DisplayName%%.

For a complete list of attributes that can be used in disclaimers and personalized signatures, see the description for the ADAttribute property in Transport Rule Predicates.

Use of a Separator Line

You may want to clearly identify in an e-mail message where a disclaimer starts or ends and where the original message content starts or ends. In Exchange 2010, you can use the HTML tag <HR> to create a separator line. You can also use inline CSS styles in HTML tags to add lines or borders around the HTML disclaimer message.

Placement of the Disclaimer

When configuring a transport rule to add a disclaimer, Exchange lets you decide whether to prepend or append the disclaimer to the message. When you prepend the disclaimer to the message, the disclaimer is inserted before the text of the newest message. When you append the disclaimer to the message, the disclaimer is inserted at the bottom of the message thread. Exchange doesn't check whether previous disclaimers have been added.

The following is an example of disclaimer text used to create a HTML disclaimer with an IMG tag and embedded CSS:

<div style="font-size:9pt;  font-family: 'Calibri',sans-serif;">
%%city%%, %%state%% %%zipcode%%</div>
<div style="background-color:#D5EAFF; border:1px dotted #003333; padding:.8em; ">
<div><img alt="Fabrikam"  src="https://fabrikam.com/images/fabrikamlogo.png"></div>
<span style="font-size:12pt;  font-family: 'Cambria','times new roman','garamond',serif; color:#ff0000;">HTML Disclaimer Title</span></br>
<p style="font-size:8pt; line-height:10pt; font-family: 'Cambria','times roman',serif;">This message contains confidential information and is intended only for the individual(s) addressed in the message. If you are not the named addressee, you should not disseminate, distribute, or copy this e-mail. If you are not the intended recipient, you are notified that disclosing, distributing, or copying this e-mail is strictly prohibited.  </p>
<span style="padding-top:10px; font-weight:bold; color:#CC0000; font-size:10pt; font-family: 'Calibri',Arial,sans-serif; "><a href="http://www.fabrikam.com">Fabrikam, Inc. </a></span></br></br>


The preceding HTML disclaimer is used as an example. It isn't intended for use as-is.

Behavior of the Disclaimer with Messages That Can't Be Modified

Some messages, such as encrypted messages, prevent Exchange from modifying the content of the original message. Exchange allows you to control how your organization handles these messages. When you create a disclaimer, you can decide whether to wrap a message that can't be modified in a message envelope that contains the disclaimer, reject the message if a disclaimer can't be added, or ignore the disclaimer action and deliver the message without a disclaimer.

The following list describes each fallback action:

  • Wrap   If the disclaimer can't be inserted into the original message, Exchange encloses, or "wraps," the original message in a new message envelope. Then the disclaimer is inserted into the new message.


    If an original message is wrapped in a new message envelope, subsequent transport rules are applied to the new message envelope, not to the original message. Therefore, you must configure transport rules with disclaimer actions that wrap original messages in a new message body after you configure other transport rules.


    If the original message can't be wrapped in a new message envelope, the original message is not delivered. The sender of the message receives a non-delivery report (NDR) that explains why the message was not delivered.

  • Reject   If the disclaimer can't be inserted into the original message, Exchange doesn't deliver the message. The sender of the message receives an NDR that explains why the message wasn't delivered.

  • Ignore   If the disclaimer can't be inserted into the original message, Exchange delivers the original message unmodified. No disclaimer is added.

Using Exchange Hosted Services

Transport messaging policies are enhanced by or are also available as a service from Microsoft Exchange Hosted Services.

Exchange Hosted Services is a set of four distinct hosted services:

  • Hosted Filtering, which helps organizations protect themselves from e-mail-borne malware

  • Hosted Archive, which helps them satisfy retention requirements for compliance

  • Hosted Encryption, which helps them encrypt data to preserve confidentiality

  • Hosted Continuity, which helps them preserve access to e-mail during and after emergency situations

These services integrate with any on-premises Exchange servers that are managed in-house or Hosted Exchange e-mail services that are offered through service providers. For more information about Exchange Hosted Services, see Microsoft Exchange Hosted Services.

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