Posted on by Achim D. Brucker, licensed under CC BY-ND 4.0.

Unsanitize Safelinks

Both the home/personal online offerings of Microsoft Outlook (e.g., Outlook.com, Office 365 Home, or Office 365 Personal) and the professional Office 365 offerings (e.g., as part of Office 365 Advanced Threat Detection) might rewrite links in received emails with the goal of protecting users against certain threats (e.g., phishing).

For various reasons, one might to rewrite these “safelinks” back into their original form.

The script unsantize-safelinks does exactly this. This can, for example, be used for displaying mails nicely in mutt or other text-based mail programs. In your “.muttrc” you need to add/edit the following configuration:

set display_filter="unsanitize-safelinks"

If you want to also rewrite the links when using tools such as urlscan, use:

macro index,pager \cb "<pipe-message> unsanitize-safelinks| urlscan<Enter>"

And the following trick rewrites the links prior to editing a message (e.g., when replying):

set editor ="unsanitize-safelinks -i %s && $EDITOR %s"

Finally, if links should be rewritten when viewing the HTML-part, you need to edit your .mailcap entry for type text/html:

text/html; unsanitize-safelinks -i --html %s && /usr/bin/sensible-browser %s; description=HTML Text; nametemplate=%s.html

Availability

The project is licensed under a 2-clause BSD license and available at: https://git.logicalhacking.com/adbrucker/unsanitize-safelinks.