Fax file naming

Fax files, both inbound and outbound, start with the same information.

[date time]_[from number]_[to number]

The date time is in the ISO 8601 format with all dashes and colons removed and no time zone information. The time zone is Central Standard Time. The technical format is yyyyMMddTHHmmss. That format translates to [full year][double digit month][double digit day]T[24 hour hour][minute][second].

For received faxes, the number of pages follows the last underscore.

For sent faxes, the original PDF file name follows the last underscore.