Set up a custom do-not-rewrite URLs list using Office 365 ATP Safe Links

With Office 365 Advanced Threat Protection (ATP), your organization can have a custom blocked URLs, such that when people click on web addresses (URLs) in email messages or certain Office documents, they are prevented from going to those URLs. Your organization can also have custom "do not rewrite" lists for specific groups in your organization. A "do not rewrite" list enables some people to visit URLs that are otherwise blocked by ATP Safe Links in Office 365.

This article describes how to specify a list of URLs that are excluded from ATP Safe Links scanning, and a few important points to keep in mind.

Set up a "do not rewrite" list

ATP Safe Links protection uses several lists, including your organization's blocked URLs list and the "do not rewrite" lists for exceptions. If you have the necessary permissions, you can set up your custom "do not rewrite" lists. You do this when you add or edit Safe Links policies that apply to specific recipients in your organization.

  1. Go to https://protection.office.com and sign in with your work or school account.

  2. In the left navigation, under Threat management > Policy > Safe Links.

  3. In the Policies that apply to specific recipients section, choose New (the New button resembles a plus sign ( +)) to create a new policy. (Alternatively, you can edit an existing policy.)

    Choose New to add a Safe Links policy for specific email recipients

  4. Specify a name and description for your policy.

  5. In the Do not rewrite the following URLs section, select the Enter a valid URL box, and then type a URL, and then choose the plus sign (+).

  6. In the Applied To section, choose The recipient is a member of, and then choose the group(s) you want to include in your policy. Choose Add, and then choose OK.

  7. When you are finished adding URLs, in the lower right corner of the screen, choose Save.

Note

Make sure to review your organization's custom list of blocked URLs. See Set up a custom blocked URLs list using ATP Safe Links.

Important points to keep in mind

  • Any URLs that you specify in the "do not rewrite" list are excluded from ATP Safe Links scanning for the recipients that you specify.

  • When you specify a "do not rewrite" list for an ATP Safe Links policy, you can include up to three wildcard asterisks (*). Wildcards (*) are assumed for entries such as contoso.com, which do not explicitly include prefixes or subdomains, like http:// or https://. This means an entry, such as contoso.com is similar to *contoso.com* for your "do not rewrite" list.

  • If you already have a list of URLs in your "do not rewrite" list, make sure to review that list and add wildcards as appropriate. For example, if your existing list has an entry like http://contoso.com/a and you want to include subpaths like http://contoso.com/a/b in your policy, add a wildcard to your entry so it looks like http://contoso.com/a*.

  • Do not include a forward slash (/) in the URLs that you specify in your "do not rewrite" list. For example, rather than enter contoso.com/ in your "do not rewrite" list, enter contoso.com.

The following table lists examples of what you can enter and what effect those entries have.

Example Entry What It Does
*contoso.com*
Allows specific recipients to visit a domain, subdomains, and paths, such as http://www.contoso.com, https://www.contoso.com, https://maps.contoso.com, or http://www.contoso.com/a
http://contoso.com/a
Allows specific recipients to visit a site like http://contoso.com/a, but not subpaths like http://contoso.com/a/b
http://contoso.com/a*
Allows specific recipients to visit a site like http://contoso.com/a and subpaths like http://contoso.com/a/b

Office 365 Advanced Threat Protection

ATP Safe Links in Office 365

Set up ATP Safe Links policies in Office 365

Set up a custom blocked URLs list using ATP Safe Links

View reports for Office 365 Advanced Threat Protection

Permissions in the Office 365 Security & Compliance Center