Disclaimer Rules in Exchange Online - Prevent Duplicates

Copper Contributor

Currently working on a set of disclaimer rules in Exchange Online to create a company wide signature, as other cloud solutions for appending signatures correctly (like CodeTwo or Exclaimer) are out of the budget for this year.

Created a set of rules, but finding that the signatures are duplicating and would like to prevent this by using the exclusion policy. In trying a few different exclusions it will not match to portions of the HTML or even text that is added.

The rules so far:


  1. Signature header (style sheet)
  2. Display Name
  3. Company name and address
    1. Company Name with URL
    2. street address, city, province, postal code
  4. Direct number
    1. Using the %%HomePhone%% attribute
    2. A dynamic distribution group is used to populate with those AD Objects that have this property populated
    3. This rule only applies to those in the dynamic distribution group
  5. Office number
  6. Fax number
    1. same dynamic distribution group concept as the direct number

Tried using commented code, <!-- company_name signature --> but it is removed when the other person replies. Using the exact string for the address that is generated without formatting, and it still seems to include it.

For example, address would be displayed as "12345 - 321 Street, Ottawa ON, K2J 0K6". Tried the whole string with and without quotations, portions of the string, the HTML code and portions of it, and it still seems to append another copy of the signature in longer email chains.


Using GPOs to push out a standard signature did come up in the discussion, though we are doing this to target the mobile only users as most end users do not have workstations. And, trying to minimize any administrative overhead as most mobile only users are seasonal; need to avoid potentially missing this step during user setup and without having to set all users signatures via scripting.


As the version of Exchange we had on premises was an older version we are wanting to avoid having to bring the server back up to flow mail back through an old version of the disclaimer software that was used before migrating their email solution to Office 365 and Exchange Online.

2 Replies

There is no perfect method to avoid duplication when using disclaimers, I'd recommend using client-based signatures instead. Or, you can ditch some $$$ for one of the 3rd party vendors that specialize with signature management and have solutions in place to detect/remove duplicates.

For our client base we normally utilize Exclaimer or Exclaimer Cloud for signature management, though some of our clients do opt out of the services due to the cost.


Client-based signatures so make more sense, and since we can set them via PowerShell it will apply even to the users that only work while mobile, and after messing around with the exclusion policies it is starting to look like we'll need to add this to our user creation processes.


Thank you for the prompt reply Vasil!