Cause

By default, PGP Desktop versions 9.5 and below are restricted from processing messages destined for custom (i.e. non-SMTP) address spaces. This restriction is due to limitations in granular policies that enable PGP Universal Server to process only SMTP addresses. As a result of this restriction, messages destined for custom address spaces are automatically blocked by PGP Desktop versions 9.5 and below.

 

Resolution:

Upgrade PGP Desktop

Beginning with PGP Desktop 9.9.1, if an email message is destined to a configured custom address space such as [FAX:00123456789], PGP Desktop now correctly sends the email message unencrypted.

The messaging proxy in PGP Desktop 9.9.1 can process email messages destined for a custom address space (such as a Microsoft Exchange®Fax Connector) with an address such as: 'FAX:00123456789'. To enable this feature, there are two PGP Desktop preferences that are manually configured:

MAPIBlockFAXaddresses
Values: True and False (Default)

By default, we allow emails addressed to only custom address recipients that match the restrictions: any customaddressspace addresses that have numbers and characters: 0123456789+-(),*# and a space.

For example: the addresses are valid and allowed

'FAX:111222333##LINE1'
'FAX:##LINE1'
'FAX:111222333##'
'FAX:111222333##LINE1##LINE2'

If the value for the preference is set to True, PGP Desktop will block emails that are addressed to custom address recipients.

MAPIfaxAddressSpaceList
Values: This is a list of address spaces separated by semicolons.

For example: RFAX;DEDUSFAX;FAXT; FAXW2K.

To determine whether an address is a valid FAX address or not, MAPI will check if the address space is part of MAPIfaxAddressSpaceList. If the address is valid, MAPI will allow the address to pass through, otherwise it is blocked.

The MAPIBlockFAXaddresses preference will always take precedence. If set to "True", emails addressed to custom addresses will be blocked no matter the setting for the other preferences.

If the preference is set to False, PGP Desktop checks if the address space is listed in the MAPIfaxAddressSpaceList and if listed, allows the address to pass through.


Conditions:

If there is an unresolved address in the message, the message is blocked.
If the MAPIBlockFAXaddresses is set to True and there is a fax address in message, the message is blocked.
If the MAPIBlockFAXaddresses is set to False and there is a fax address and a smtp address in message, the message is blocked.
If the MAPIBlockFAXaddresses is set to False, and there is only fax addresses in message, the message is sent in the clear (unencrypted).