PGP: Message is blocked - recipient email address could not be resolved. Error code: [0xa1010004].

CAUSE

The MAPI address space in PGP Desktop has to be configured to allow specific FAX address spaces.

SOLUTION

**Add the following values to PGPprefs.xml **
<key>MAPIfaxAddressSpaceList</key>
<string>FAX</string>
-To find PGPprefs.xml, go to \username%\UPM_Profile\AppData\Roaming\PGP Corporation\PGP \PGPprefs.xml

-Edit PGPprefs.xml in notepad.

-Find <key>MAPIfaxAddressSpaceList</key>

-Look next text to this string, it will show as <string></string>.

-Replace to <string></string> as <string>FAX</string>,

Note: Same will be performed in entire PGPprefs.xml file wherever you get <key>MAPIfaxAddressSpaceList</key>

-Once it will replace, text will be shown as below.

<key>MAPIfaxAddressSpaceList</key> <string>FAX</string>,

-Log off and relogin back to PC, and check fax services. It should work.