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  • Identifies file type
  • Associates file extensions
  • Monitors associations
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File Extension PNM

What is File Extension PNM?

File Extension PNM Recommendation:

Run a Free Scan to check for File Extension PNM related errors & to optimize PC performance.

File Extension PNM Description:

Described as a WinPMail/Mercury IMAP UID mapping file, the PNM file extension is part of the Pegasus Mail and Mercury Mail Transport System application developed by David Harris.

Aside from using the Post Office Protocol (POP) in electronic mails today, the Internet Message Access Protocol (IMAP) allows any user to access and manipulate email messages in a specific server. The file with the .pnm extension holds directives that allow both applications to perform basic IMAP functions, such as:

* creation, deletion, and possible modification of existing mailboxes

* Checking for new messages within the specified mail server

* Permanent removal of messages from the mail server

* Changing email configuration settings (depends on the services and attributes of your mail server)

* Clearing flags

* RFC2882 and RFC2045 Parsing

* Searching and retrieving of message portions, attributes and text.

One unique quality of the PNM file used in Pegasus Mail and Mercury applications is the mapping of Unique Identifier (UID) message attributes used in IMAP. UID is a 32-bit value assigned to each message in ascending order (meaning that the new message will be assigned a higher number than the previous message). Each UID in every message is unique, but not necessarily sequential.

In a PNM file, there are two main values that help in UID handling: 1) the next unique identifier value, and 2) the UID validity value. Both of which are considered as main components of the PNM file format.

The next UID value is actually the soon-to-be assigned predicted value to new messages in your mail server's mailbox, and with the following characteristics:

* The next UID value must not change unless there's a new message added to the mailbox

* And the next UID must change every time a new message is added to the mailbox.

The UID validity value uses a 32-bit data representation of the creation date/time of the mailbox, and returns the UIDVALIDITY response code, which is associated with the untagged "OK" response at each mailbox's selection.


David Harris

Author URL:

Applications associated with file extension PNM:

Pegasus Mail, Mercury

Common Path:

(user defined)

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