Page updated 1 December 2022

Go to TopIntroduction

An INI file holds data necessary for the initialisation of a program or processes used within it. Most modern programs hold initialisation data in the Windows registry. However, nPOPuk, which is designed to be portable, cannot use this technique, and uses a file "nPOPuk.ini" instead.

INI files are plain text files that are divided into sections, each of which has a heading in upper case and enclosed in square brackets. Under each heading will be a varying number of settings, each on its own line. These take the form "settingname=value". Where there is no value associated with a setting the program will use a default value.

The nPOPuk.ini file typically has three headings:

Contains settings common across all mail accounts.
Contains settings for each dialup connection. Passwords are encrypted.
Contains settings for the default mail account. Additional accounts and Saveboxes generate further [MAILBOX-x] sections (with increasing values of "x").

Advanced users often customise programs by editing their INI files using a text editor. However, nPOPuk is provided with an Options Editor that will access the vast majority of settings even an advanced user is likely to want to edit. Using the internal Options Editor also avoids the need to close nPOPuk first. (Using an exernal editor has the disadvantage of not having a mechanism for forcing nPOPuk to re-read the settings from the revised file.)

Go to TopImportant Note

The nPOPuk.ini file not only holds program settings, but also data about the most recently downloaded mail. Windows' System Restore facility takes regular snapshots of INI files, and depending on the version of Windows and the location of the file that may include nPOPuk.ini. Should your computer develop a problem and a System Restore be executed, the record of each account's transactions with the server may be reset to those applicable at the system restore date, effectively corrupting the file. The simplest solution is to protect the file from reversion, by renaming it (e.g. before undertaking a System Restore. Once the restore is completed the nPOPuk.ini file should then be overwritten with your renamed file. However, there is a more sophisticated alternative that uses a special inifile setting within the nPOPuki.ini file.

Go to TopOptions Editor

The Options Editor

WARNING: Editing an INI file is potentially dangerous as invalid values can crash nPOPuk and may destroy mail data. It is also possible to set illegal values that will impede the performance or make the program unusable.

The Options Editor is restricted to the settings in the [GENERAL] section of the INI file. The editor is accessed by holding down the SHIFT key while selecting "Global Options..." from the File menu of the main window. Initially a confirmation dialogue appears before the editor itself opens.

New values for the settings are parsed and come into effect when the editor is closed by clicking the OK button.

Most users will not need to use the Options Editor as many of nPOPuk.ini's entries are controlled by dialogue box settings and are written to nPOPuk.ini as the dialogue "OK" button is clicked. The Options Editor is provided to permit the editing of entries, described in the following section that can only be edited manually.

Go to TopSettings

This section is restricted to discussion of settings that can only be edited manually (Those listed as "Undocumented", are part of the base code written by Tomoaki Nakashima that appear to have no means of being edited within the Program and whose function has not been fully investigated by the nPOPuk programming team.) For those who wish to explore further the full range of settings a Commented INI File is available that provides some further information.

NOTE: Comment lines in the file may start with either a semi-colon (;) or a hash (#).

Go to TopGeneral Settings - Manual Edit

The settings listed here are from the [GENERAL] section and limited to those that can only be edited manually. Items are listed in the order that the entries appear in the file.

All values are shown with their default value. Note that text values are always enclosed in quotes.

Determines the location of nPOPuk's Mailbox and Address Book files. The default is the program folder. Takes either a full drive and file path, or relative path.  e.g.:
DataFileDir="C:\My Documents\nPOPuk data\"
1.  Ensure that the named folder exists. Move all files, apart from nPOPuk.exe and nPOPuk.ini, from the program folder to the named folder before re-launching nPOPuk.
2.  nPOPuk.ini may also be moved to this folder but ONLY IF the program is launched with an appropriate Command Line Option.
Stores the full path of last used backup directory (See: Backup... on the Main Window File menu). The string is NULL if the backup feature has not yet used.
The revision level of the program that was used to create the file. It is incremented when a new feature is added that is not supported by previous versions. As such, you are discouraged from changing the value manually.
Controls the generation of a file (nPOPuk.log) which logs the server communication and optionally further debugging information. At the start of each nPOPuk session any existing nPOP.log file is deleted. A new one is generated as nPOPuk next terminates and only if there has been material to report in that session, so the log does not normally grow to any significant size!
0 = No Log
1 = Generate nPOPuk.log
NOTE: Values >1 may enable additional messages, particularly on beta test versions
Sets the font used in the body of the main Main Window and header areas of the Mail View and Edit windows.  e.g.:
Sets the font size used in the body of the main Main Window and header areas of the Mail View and Edit windows.  e.g.:
1. Changing the default setting has no effect unless a font has been specified under LvFontName=.
2. As the space allowed in certain windows/dialogues does not change to allow for larger text than the default altering this setting is not recommended.
Sets the font weight used in the body of the main Main Window and header areas of the Mail View and Edit windows.
0 = Normal
700 = Bold
NOTE: Not fully tested. Other values may be possible.
Sets the font style used in the body of the main Main Window and header areas of the Mail View and Edit windows.
0 = Plain
1 = Italic
Used to select a different character set for the LvFont.
0 = ANSI
1 = Default
2 = Symbol
etc. (See: Determining the Character Set Used by a Font at the Microsoft site.)
Sets the multiplier for calculating the size of the first panel in the Status Line. This panel is calculated by the formula:
(Width of Panel in Pixels) = (Characters in Panel) * (StatusBarCharWidth)
Variation from GMT, A -/+ prefix indicates earlier or later than GMT. A four digit value where the first two digits represent hours and the second two the minutes. Daylight savings Times are allowed for automatically.  e.g.:
TimeZone="+0930" (Nine and a half hours later than GMT).
NOTE: If this setting is blank (the default) nPOPuk uses the Windows time zone.
Controls whether nPOPuk runs minimised.
0 = Opens as controlled by Windows
1 = Always Opens Minimised
NOTE: This option over-rides the standard Windows facility for shortcuts, or items in the Startup folder, which allows a program to be run Minimised, Maximised or in a Normal Window.
Controls the behaviour of a left-click on the Notification Area icon.
0 = Makes nPOPuk the active window.
1 = Switches Main Window between being minimised and the active window
This setting is controlled through the Initialise dialogue, so would not be documented here but for the complex interaction with the similarly named setting in the [MAILBOX-XX] section
Controls whether nPOPuk initialises account data on launch
0 = Details of the most recent message found at the POP Server are retained.
1 = Details of the most recent message found at POP server are deleted. (In effect, this option initialises ALL accounts on launch.)
2 = Fills in from 1 and applies to [GENERAL] and [MAILBOX-XX] entries. The [MAILBOX] setting can't decrease the [GENERAL] one. If [GENERAL]'s StartInit=2, then all Mailboxes will behave as though StartInit=2 (regardless of what they have set). If [GENERAL]'s StartInit=1, then this will be used for any Mailbox that doesn't have StartInit=2. If [GENERAL]'s StartInit=0, then the Mailbox setting prevails.
These two settings control the Main Window display. With appropriate settings it is possible to get Large or Small icons displays rather than the default "Details" view. The values are OR'ed into the style when creating the main (ListView) window. You have to know what bits to set for the style you want. (See:
Sets the minimum width below which the mailbox pane cannot be resized by dragging the separator bar
Sets the minimum height below which the preview pane cannot be resized by dragging the separator bar
PreviewHeader="From: %F\nTo: %T\n{CC: %C\n}Subject: %S\nDate: %D\n\n"
Determines which headers to show in the preview pane. For a description of the codes available see the Place Holders page
Sets amount of time a message must be in the preview window before being marked read. A positive number is the time, in seconds; 0 means the message should be marked read as soon as it is previewed; a negative number means previewing a message never counts as reading it.
Sets the number of Saveboxes to exist to enable the appearance of the Transfer dialogue (rather than a cascading menu) when Moving/Copying to a Savebox.
<=n = Cascading menu appears
>n = Transfer dialogue appears
Determines the effect of the DEL, SHIFT-DEL and CTRL-DEL keystrokes.
DelIsMarkDel= Keystroke Accounts Saveboxes
=1 DEL Mark to Delete Delete from List
CTRL-DEL Mark to Delete No effect
SHIFT-DEL Delete from List Delete from List
=0 DEL Delete from List Delete from List
CTRL-DEL Mark to Delete No effect
SHIFT-DEL Delete from List Delete from List
Setting =0 returns the behaviour of the DEL and CTRL-DEL keystrokes to that of nPOPuk versions prior to v2.11 (SHIFT-DEL had no effect prior to v2.11).
Controls scrolling of Inbox accounts in the Main Window.
0 = No scrolls takes place
1 = Scrolls so the most recently downloaded message is visible.
(This doesn't always work! More research needed!)
Under construction!
Saves data files after all principal actions affecting data.
(There are a number of things that don't cause an autosave, e.g. marking messages read/unread/replied/forwarded, changing the Word wrap status on the Mail View window and Delete attach on the Main window.)
0 = Off
1 = On (Saves after all accounts have been checked/updated)
2 = Really on (Saves after each account is checked/updated)
Controls the appearance, on exit, of a dialogue to prompt to save all files.
0 = Off
1 = On
1. For the command line option "/q" to work without interruption, set to zero.
2. Implemented at the request of PocketPC users as it can take a long time to write to flash memory on that platform. The need for this facility should have been superseded by the Load Mailboxes settings on the Advanced tab of the Global Options dialogue.
Fixes the Content-Type header line of messages sent from mail programs that are not compliant with RFCs.
0 = Content-Type header is not changed
1 = For a multipart/alternative message sent by Apple Mail, nPOPuk will check to make sure that the parts are in fact alternatives, and that none of the parts contains an attachment. If an attachment is found, the Content-Type header will be changed to multipart/mixed.
2 = checks multipart/alternative for all mailers, not just Apple Mail.
Controls the column to be searched for a matching entry in the Address Book.
0 = Mail Address
1 = Comment
Controls the default setting for the "Add new recipients to address book" check box that appears on the Property Dialogue when creating a reply.
0 = New Recipients NOT added
1 = New Recipients added
If set to a string equivalent to a group/category name, the Address Book will open showing only addresses in this group/category. e.g.:
Controls the sending of EHLO/HELO command. According to:, EHLO replaces older HELO command for SMTP clients that support SMTP service extensions. Can be issued at the start of the session to see which extensions the server supports.
0 = HELO sent (EHLO is used automatically for SmtpSSL or SmtpAuth.)
1 = EHLO sent
Controls the domain sent to the SMTP server as part of the authentication process.
The default is the Mail Address for the sending account. e.g.:
Normally, POP before SMTP is used for an account's SMTP server only as an authentication device and mail is not collected. This setting allows mail to be collected.
0 = Mail is collected from the POP3 server
1 = Mail is not collected from the POP3 server
Assumed to be a delay in milliseconds between negotiation with the POP server and SMTP server with the POP before SMTP setting is used for an SMTP server.
(Not yet confirmed!)
Designed to provide a work around for occasions when GMail is having problems and it erroneously reports 0 messages on their server.
0 = Deletes all mail from accounts when the POP server reports no mail
1 = Keeps mail in spite of POP server reporting no mail
ReSubject="Re: "
Text inserted as prefix in subject line of replies.
FwdSubject="Fwd: "
Text inserted as prefix in subject line of forwarded mail.
An address, or comma separated list of addresses, entered here will appear above any others on the ReplyTo: drop down list on the Mail Property dialogue.
1.  If E-mail software finds a "Reply-To:" line in the message headers any reply will go to that address, rather than the one in the "From:" line.
2.  Do not confuse this setting with the similarly named ones in each [MAILBOX-x] section
Under Construction! Used for line-breaking in double-byte character sets (eg Kanji)
The ca.pem file is used to check the server's identity. It is an X.509 type of root certificate and may be needed if the verify boxes are checked in the setup SSL section. Files containing the certificates of major certificate authorities can be downloaded from and from
Sets caching of the server (SMTP and POP) IP addresses. When OFF nPOPuk is forced to resolve the server name to an IP address every time it sends mail. Not recommended!
0 = IPCaching OFF
1 = IPCaching ON
Under Construction!
Apparently allows filenames to use extended character sets.
Controls the appearance of the "New Mail" dialogue.
0 = Shows only if nPOPuk is not the active window
1 = Shows whether or not the nPOPuk window is active
Sound file to play after a server update when no new mail arrives. Takes a full or relative path.  e.g.:
Controls whether sound files are played when selecting messages in the main window.
0 = No sound is played
1 = The appropriate sound file (if present in the Resource subdirectory) is played:
New Mail NEW.WAV
Partially downloaded mail PARTIAL.WAV
Fully downloaded mail FULL.WAV
Mail with attachment ATTACH.WAV
Mail with HTML attachment ATTACH_HTML.WAV
Mail without icon NO_ICON.WAV
Unread mail UNREAD.WAV
Read mail READ.WAV
Mail marked for download DOWNLOAD.WAV
Mail marked for deletion DELETE.WAV
Mail marked for sending SEND.WAV
Sent mail SENT.WAV
Error reported on sending mail ERROR.WAV
Mail Flagged for Follow-up FLAG.WAV
Automatically clear Send and Receive Error Warning Dialogues
0 = Clear dialogue manually
1 = Clear dialogue automatically
Allows auto check activity to continue!
Sets the timeout (in seconds) for various network operations.
Determines whether the Outbox should automatically be reordered to keep unsent messages (drafts) at the bottom.
0 = Do not reorder the messages
1 = Reorder automatically
Relative or full path and filename of the program to use as the external viewer. If no application is specified, the application associated with the file type defined at ViewFileSuffix= is launched.  e.g.:
holds any command line parameters of application specified at ViewApp=.  e.g.:
ViewAppCmdLine="/P $npop_view.txt"
1.  For the command line parameters to function an application must be specified at ViewApp=.
2.  nPOPuk generates a file with the name "$npop_view" and the file extension specified under ViewFileSuffix=, so the example here will print the selected message when Notepad is specified under ViewApp=. (See the Printing Mail page for more examples.)
The file extension to be used when generating the file to load into an external viewer application.
1.  Consider using "htm" to display and print HTML mail. (See the Printing Mail page for more examples.)
2.  The setting is also used by the function that strips HTML tags from messages with no HTML part.
ViewFileHeader="From: %f\nTo: %t\n{Cc: %c\n}Subject: %s\nDate: %d\n\n"
Text and coding used to reproduce header information when mail is exported to the external viewer. The codes available are explained on the Place Holders page.:
Controls closure of the Mail View window when external viewer is opened.
0 = Does not close.
1 = Closes.
Toggle use of the Mail View window.
0 = File defined at ViewFileSuffix=/ViewApp= will act as external viewer
1 = File defined under ViewFileSuffix=/ViewApp= replaces the Mail View window.
Controls whether Attached file dialogue appears
0 = Dialogue appears (Open/Save options)
1 = Dialogue by-passed (Attached files that are messages, i.e. RFC822 or text/plain in digests, will open. The Attached file dialogue shows for other types.)
Controls whether a cursor appears in the Mail View window
0 = No cursor
1 = Cursor appears
With a cursor it becomes possible to use the keyboard to select text.
Controls whether a list of attachments is appended to the message body. Double-clicking on the attachment name will open the associated file.
0 = No list
1 = Attachments are listed
Full or relative path and filename of program to use as the external editor. If no application is specified, the application associated with the file type defined at EditFileSuffix= is launched.  e.g.:
EditApp="..\..\Program Files\NOTEPAD.EXE"
Any command line parameter to be used when launching the external editor.
NOTE: For the command line parameters to function an application must be specified at EditApp=.
The file extension to be used when generating the file to load into the external editor application.
1.  nPOPuk generates a file with a random numeric name and the file extension specified here.
2.  This file is merged with Sendbox.dat then deleted as the editor is closed.
3.  Unless an application is specified at EditApp=, the default editor for this file type is opened.
4.  If an unrecognised file extension is set and EditApp= remains empty, then nPOPuk reverts to the internal editor.
Toggle use of the Mail Edit window.
0 = Mail Edit window used for editing.
1 = An external editor is used for editing.
Controls the name of the sub-folder of the data directory (See DataFileDir=) to which an attached file is initially extracted when it is opened (rather than saved). If no name is specified, the data directory is used.
Controls the retention of opened files (See AttachPath=).
0 = Extracted files are retained when nPOPuk is closed
1 = Extracted files are given an "_attach_" file name prefix. On exit of nPOPuk the following deletions occur:
  • All files with the "_attach_" prefix found in the folder indicated by the AttachPath= setting
  • If it exists and is empty, the folder specified in the AttachPath= setting
Controls handling of mail with no plain text part. (For a more refined approach, use the ViewApp= and associated settings.)
0 = Display Full Message, including all HTML tags
1 = Strip HTML tags, preserving any "http://" Links
NOTE: nPOPuk normally only displays the plain text part of a message. To view any HTML part, either use View Source or the External Viewer.
Full or relative path and filename of program to use to replace the system's default browser when clicking URL links in nPOPuk.  e.g.:
URLApp="C:\Program Files\JanSoft\Act10\Act10.exe"
URLApp="C:\Program Files\\Mozilla\mozilla.exe"
Holds any command line parameters of application specified at URLApp=. This will most commonly be needed by those launching a .bat file at URLApp= and needing to include the URL to be launched as a parameter. e.g.:
1. For the command line parameters to function an application must be specified at URLApp=.
2. The command processor, CMD.exe, will fail to open a URL that includes &'s, so any url that includes more than one parameter, such as:
needs to be quoted to avoid CMD.exe misinterpreting it and not passing it to the browser. In the example %1 stands for the URL that nPOPuk parsed from the message body.
Specifies the path and name of the file that will act as the "nPOPuk.ini" file. e.g.
this setting is designed to make nPOPuk resistant to corruption as a result of a Windows System Restore operation. In use it will be the only line in the nPOPuk.ini file. The contents of the "true" nPOPuk.ini will instead be copied to the named file, in the example above "config.txt".
EXPLANATION: Windows sometimes (it varies between versions of Windows and exactly where the nPOPuk.ini file is placed) will restore the nPOPuk.ini file, replacing the current version with an old one from the restore point used.. Because the nPOPuk.ini file records data on the number of messages in each mailbox and the ID of the final message, replacing the current version with an old version can have extremely undesirable results. For this reason, the use of this setting is strongly recommend for use on any Win32 installation.

Go to TopMailbox Settings - Manual Edit

This second group of settings are from the [MAILBOX-x] section(s). Only the following settings are neither controlled by the Accounts Settings dialogue nor updated during communication with the server.

Allows the setting of a sound file to be played when new mail arrives in the account. A different sound file can be chosen for each account.
For each Mailbox, an address entered here will appear as the default, replacing the (Omit) entry that otherwise appears in the Replyto: box on the Mail Property dialogue.
NOTE: Do not confuse this setting with the similarly named one in the [GENERAL] section.
Controls whether nPOPuk initialises account data on launch
0 = Details of the most recent message found at the POP Server are retained.
1 = Details of the most recent message found at POP server are deleted.
2 = Fills in from 1 This setting can't decrease the [GENERAL] one. If [GENERAL]'s StartInit=2, then all Mailboxes will behave as though StartInit=2 (regardless of what individual [MAILBOX]es have set). If [GENERAL's StartInit=1, then this will be used for any Mailbox that doesn't have StartInit=2. If GENERAL's StartInit=0, then the Mailbox setting prevails.
NOTE: Do not confuse this setting with the similarly named one in the [GENERAL] settings section.

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