Skip to content

What You Can & Can’t Do in Microsoft Exchange Signatures

Brought to you by Exclaimer

With Exchange Server 2000 and 2003, an IT admin required Visual Basic Script (VBS) knowledge to add an email disclaimer to an outgoing message. This made email signature management difficult at best.

When Exchange 2007 was released, it introduced Hub Transport Rules for the first time. This allowed a company to apply a disclaimer to a message created in the Exchange Admin Center.

Exchange 2010 made email signature management slightly easier. Creating a signature using Exchange in-built disclaimer feature allowed for additional customizable elements such as Active Directory (AD) Attributes to personalize all users’ signatures. It also allowed for the creation of HTML email signatures with inline CSS by using the ‘Specify disclaimer text’ feature.

However, it’s well known that the Exchange disclaimer function has never really been designed with high-quality HTML in mind. The clue is in the name: as far as Microsoft is concerned, this function is to be used to enter text for a legal disclaimer, not for an HTML email signature design.

The same email signature and disclaimer limitations have appeared across all versions of Microsoft Exchange. These include:

  • No email signature template library

  • No WYSIWYG HTML editor

  • No Rich Text Format support

  • No way to place a signature under a reply or forward

  • No ability to hide blank AD fields in contact details

  • No way to embed images into a signature

  • Not being able to see signatures in the Sent Items folder

1. You CAN pull contact details from Active Directory

Exchange 2010 and above has support for pulling contact information from Active Directory to populate email signature templates. This is done in the disclaimer transport rules by specifying AD Attributes and placing them between two percentage symbols on either side. For example, %%DisplayName%% will pull in the sender’s Display name.

2. You CAN create an HTML email signature

With Exchange 2010 came the ability to use HTML tags in signatures, which allowed for more email signature designs. However, if an email is sent in plain text, any customized signature elements are stripped out. This often happens on mobile devices particularly with iOS.

You can create HTML email signatures in Exchange.

3. You CAN’T create signatures using a WYSIWYG editor

Although the Exchange Management Console provides you with an interface to create your disclaimer rule, you cannot use a 'What You See Is What You Get' editor to design an email signature.

Instead, you select from pre-defined options and test your signature with a live email send once configured.

4. You CAN use custom fonts, sizes or colors

With HTML support in Exchange 2010, you can customize a signature with dynamic elements. Options include using signature colors with hex codes, different font sizes, fonts using inline CSS and inserting hyperlinks.

Exchange Signature using different coloured fonts

5. You CAN'T embed images

If you try to copy-and-paste an image directly into the signature, the recipient is likely to see a blank square with a red “X” in its place, or find a separate attachment added to the email message. At best, embedded images will increase the size of all emails or get stripped out by certain email clients like iOS.

To deliver images within an email signature such as a company logo, you usually have to host them online, but they won’t be automatically displayed

6. You CAN’T place signatures directly under the latest reply or forward

An issue since Exchange 2007, this means any signatures applied to outgoing messages will be placed at the bottom of the email chain.

As more emails are sent, signatures will continue to stack and stack, to the point where a conversation can flooded with signature content. This can lead to an email chain becoming unreadable and difficult to follow.

7. You CAN’T hide empty contact fields if they are blank

Although you can include AD Attributes, you cannot set them to be hidden if certain contact fields are blank. For example, if some users have a mobile number displayed, but others don’t, the field will still remain in the signature although it will be empty for the users who don’t have a mobile.

8. You CAN’T see signatures in users' Sent Items folders

As the sent email does not get updated until after the signature is applied, the sender will not be able to see it in their Sent Items folder.

9. You CAN set a fallback action

A fallback action is used if the disclaimer cannot be applied to an email such as when sending signed or encrypted messages. You have three options to choose from:

  • Wrap’ – create a new message with a signature/disclaimer, while the original message becomes a separate attachment

  • Ignore’ – send the message without a disclaimer if it cannot be modified

  • Reject’ – stop the message being sent with a bounce back or NDR to the sender

Exchange signature with a disclaimer

10. You CAN set limited time-based rules

Disclaimer rules for an Exchange signature can be applied for certain dates. For example, you could set it so the signature is applied to outgoing emails from December 1, 20xx to December 31, 20xx. However, you are unable to set a rule to reoccur due to the year being in the date.

Other Exchange signature considerations

Be aware that if you are using Microsoft Exchange 2007 or older, your options are even more limited when it comes to Exchange email signature management. You can't create an HTML email signature, use images or even get contact information from Active Directory.

Even with more recent versions of Exchange, there are still many issues that stop organizations creating the best email signature templates possible. If you want to build an Exchange email signature that works, you owe it to yourself to use third-party email signature software to automate this for you.

Try for free today Your new email signature experience
is just a few clicks away