To get Microsoft Fax to dial 1 before numbers

If you want the Windows Dialing Properties (of which dialing 1 is just one facet) to be applied to outgoing faxes, the numbers need to be entered in Contacts in the format

where +xx is the country code (+1 for the U.S. and Canada), yyy is the area or city code and zzz-zzzz is the local number.

Often imported numbers don't have this format and need to be edited, or Outlook doesn't recognize that they're formatted. See the MSKB article Microsoft Fax Does Not Process Dialing Properties for procedures to fix both existing and future numbers.

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