This article helped me today:

How to use CFMail properly

Using has its challenges. In our case, email messages sent from our CF9 application to recipients using Outlook or AOL as their mail readers was resulting in broken links and oddly formatted characters.

The culprit turned out to be the encoding of the HTML mail - the aforementioned mail user agents were detecting one character set and re-formatting the source, resulting in characters being dropped or added to the source.

The fix was to use for both a text/plain section and a text/html section in the main document, like this:

view plain print about
1<!--- be sure each variable is populated with appropriate values before running this code! --->
2<cfmail from="#from_string#" to="#strEmailTo#" subject="#strMsgSubject#" type="html">
3    <!--- headers and attachments --->
4    <cfmailparam name="List-Unsubscribe" value="<>,<#strUnsubLink#?#strClientInfoHash#>">
5    <!--- plain version of message --->
6    <cfmailpart type="text/plain" charset="utf-8">#strTextOnlyMsg#</cfmailpart>
7    <!--- HTML version of message --->
8    <cfmailpart type="text/html" charset="utf-8">#strHTMLMsg#</cfmailpart>