Including or Attaching an External File

When you select Files(s) from the Include/Attach -> menu the Include/Attach File dialog is opened. This is very similar to the Select Folders menu available through the Open ... option in the Main window Folder pull-down menu. (See Using the File Selection Window for information on using this type of dialog window.)

You can enter the path name of one or more files, separated by a Return after each name. Or, click the Show list button to see an expanded dialog that lists files in the current directory and subdirectories of the current directory. You can then select a file by clicking on a name in the list.

After you have selected a file path name the Include/Attach file data dialog is opened.

Figure: Include/Attach File Data

The Include/Attach file data dialog lets you specify how the data is to be included or attached, how it is to be encoded, and how it is described. This dialog will be shown once for each file you named in the Include/Attach File dialog. The items to be specified include:

File name

This is the name you entered in the previous dialog. If you made a typing mistake in the path name, you have the opportunity to correct it here.

Description

Here you can enter a line of descriptive information to be used as the label on the icon that will be displayed in the text at the point where the file is included. If you don't enter a description, the path name is used as the label.

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NOTE:
If you include a file in-line the Description information is not used.

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Type

This is an option menu that presents all the possible data types for an external file. The default choice in the menu will reflect Ishmail's best guess as to the data type. You can override the default by clicking the option menu button and selecting from the list.

The icon displayed in the message text will vary according to the data type. Icons Representing Included Files shows examples of icons that represent included GIF, JPEG, binary, PostScript, MPEG, and U-LAW audio files in a Composition window.

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NOTE:
The option menu is built from a file containing a list of MIME data types and file name suffixes associated with them. A default file is supplied with Ishmail, called mime.types. It is located in the lib subdirectory at the location where the product is installed. When you add entries to the mime.types file, corresponding choices are automatically added to the option menu. If you wish to override entries in the default file, you can use the $MIMETYPES environment variable to point to an alternate file.

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How should this file be included/attached?

The radio buttons labelled How should this file be included/attached? are used to select how to add the external file. Choices are:

In Message as text

Use this option to cause the contents of the external file to be copied into your message at the point where the cursor is located, as if you had typed in the data. When you do this Ishmail does not create a separate message body part. The recipient of the message will be unable to detect that the data was included from a file.

This option is intended as a shortcut to save you typing time. It is not recommended for including non-ASCII data.

In Message as a separate file

Use this option to cause the contents of the file to be copied into your message as a separate body part, at the point where the cursor is located. The body part will be identified by an icon, examples of which are shown in Icons Representing Included Files.

When the recipient of the message clicks on the icon, the appropriate viewer program will be launched (if available) to show the data contained in the file, as specified in the Mailcap File Definition.

Attached as "local to the recipient"

This is the first of the attach options, each of which place a pointer to the external file into the message. To the recipient, the icon looks the same as an included file. Clicking the icon causes the appropriate viewer program to be launched.

The local attachment option can be used when all the recipients are in the same local network, and can access common files from a server.

When you click the Attached as "local to the recipient" button the Include/Attach file data dialog expands to include extra parameter fields.

Expanded Include/Attach File Data shows an example of an Include/Attach file data dialog with expanded parameters. The section entitled Extra parameters for attached files describes the additional parameters.

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NOTE:
The recipient of the message must be able to access the attached file.

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Attached via anonymous FTP

This attach option is most frequently used when the recipients of a message are not in the same local network as the sender. It requires that the sender's network support an FTP server that can be accessed by people outside the local network.

The sender must first place the external file in a directory which is made visible to the outside world by the FTP server. Then, the file is attached to the message by providing both the path name and the network name (or IP address) of the FTP server.

This option is known as anonymous FTP since the recipients do not need a login account on the FTP server. Instead, they log in using the name anonymous, and give their e-mail address as the password. (Most MIME mail programs do this automatically.)

When the recipient clicks on the file icon in the message, the file is retrieved from the FTP server and then it is displayed. Depending on the speed of the FTP link, this may take a long time. An animated icon is displayed during the retrieval, so the recipient is aware that it is in progress.

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NOTE:
You may need to coordinate with your system administrator to get files copied into directories used by the FTP server. For security reasons, some organizations restrict access to this service.

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When you click the Attached via anonymous FTP button the Include/Attach file data dialog expands to include extra parameter fields.

Expanded Include/Attach File Data shows an example of an Include/Attach file data dialog with expanded parameters. The section entitled Extra parameters for attached files describes the additional parameters.

Attached via regular FTP

This option is essentially the same as anonymous FTP described above, except that the recipients need to have a login account on the FTP server. When the recipient clicks the icon and connection is made with the FTP server, the server will prompt the recipient for a login account name and password.

This option is more secure than the anonymous FTP option, but requires more effort to set up.

Attached via TFTP

This option also is essentially the same as anonymous FTP described above, except that it uses the TFTP program rather than the FTP program. Because of network security problems associated with TFTP many organizations do not support use of this program, so you may find this option unusable.

Attached via mail server

This option is considered the most secure way to allow people external to your network to retrieve files, though it is the most complicated to set up and has the slowest performance.

A mail server is a program which accepts e-mail messages formatted a certain way. It recognizes, among other things, requests to retrieve a file with a specific path name. It responds to the e-mail message by sending a reply message containing the requested file.

When the recipient clicks on the file icon Ishmail mails a request to the appropriate mail server. The requested file will eventually arrive as a new mail message.

The sender must coordinate with the local system administrator to make the file available to the mail server.

What type of encoding should be applied to this file?

This set of radio buttons lets you specify how, if at all, the file data should be encoded when transferred over the network. The recipient's mail tool uses this information to know how to automatically decode the file.

Electronic mail systems were originally designed to handle 7-bit ASCII characters, i.e. the U.S. English character set. All modern mail systems can now handle 8-bit ASCII, thus can use various ISO character sets for non-English alphabets. However, messages you send may pass through many different mail systems on the way to their destination, and there is no guarantee that some intermediate mail system may not be able to handle other than 7-bit ASCII. The result may be that your message is garbled in transmission. To guard against this, you can encode your message so that it will pass safely through any mail system even if it contains binary (non-ASCII) data.

There are five choices for encoding.

None

The data is not encoded. It is implied that your data contains only 7-bit ASCII characters.

8-bit

The data is marked as containing 8-bit ASCII data, but not otherwise encoded. This is really just a warning. It may cause intermediate mail systems, and the destination mail reader, to treat you message differently. You should mark your data this way if you know it contains 8-bit characters.

Quoted Printable

Your message is converted to a form that uses only 7-bit ASCII. For example, 8-bit ASCII characters are changed to an equal sign followed by two hexadecimal digits, which represent the 8-bit character code. This encoding method leaves the message mostly human-readable. However, this method doesn't work very well with non-ASCII data, mainly because the encoded message may be 2 to 3 times the size of the original.

Base 64

This encoding should be used for binary data. Like Quoted Printable, all characters are encoded so they appear as 7-bit ASCII characters. Unlike Quoted printable encoding, this method works well with any binary (ASCII or non-ASCII) data. This is the encoding method is used, for example, for file types such as Audio, GIF, and JPEG. The encoded message will be about one third larger than the original.

Base 64 encoding is a "next generation" of uuencode. It was developed to address the shortcomings in uuencode, mainly the lack of standardization of the algorithm.

uuencode

This encoding is also used for binary data. It has been in use for years and is popular. However, it is not included in the MIME specification due to lack of standardization of the algorithm, which may lead to a recipient being unable to correctly decode a uuencoded message. Ishmail supports uuencode to increase backward compatibility with other mail tools.

The file is already encoded this way

Toggle this option On if the file you are including or attaching has already been encoded. Otherwise Ishmail will encode the file automatically.

Figure: Icons Representing Included Files

Extra Parameters for Attached Files

Figure: Expanded Include/Attach File Data

The optional parameters are:

Output file name

This is default path name of the file which will be created on the recipient's system when the attached file is retrieved from the sender's system. It is not necessarily the same as the original file name. The recipient may also override this name at the time the file is retrieved.

Application type

This parameter is specified only for files of type application/octet-stream. You can specify additional type information that identifies the format of the data.

Application padding

This parameter is specified only for files of type application/octet-stream. If your system hardware has a byte size other than 8-bits, or a word size that is not a multiple of 8-bits, you specify the number of bits required for padding here.

Character Set

This parameter is required only for ASCII text files included in a message as a separate body part. You can specify which ASCII character set to use when displaying the data.

An option menu button to the right of the field shows a list of possible character set names to choose from, or type the name in the field.

If the data is included in-line, this implies using the same character set as the message body.

Other parameters

The MIME specification is evolving. Other parameters are proposed for file attachments. This field lets you add other parameters that may be defined after this version of Ishmail was released.

Expires

This is a date after which the original file may be deleted or changed. A recipient attempting to retrieve the file after this date may receive an error or stale data.

Size

This is the size of the original file. Specifying this parameter gives the recipient a hint about how long the retrieval will take and how much space is needed to hold the retrieved file.

Permission

The file can be marked as either Read Only or Read/Write. A Read Only file will not be changed before the Expiration Date. A Read/Write file may be changed at any time. Therefore, this parameter is a hint to the recipient that the file need be retrieved only once (Read Only) or should be retrieved each time the recipient looks at the data (Read/Write).

Host

This parameter is shown only for FTP or TFTP attachments. It lets you specify the name of the FTP or TFTP server. It can be a host name, such as ftp.ishmail.com, or an IP address, such as 206.196.74.36.

Directory

This parameter is shown only for FTP or TFTP attachments. It lets you specify the directory which contains the file to be retrieved. This parameter works in conjunction with the File name field. For example, if the path name of the file is /ftp/public/data.file, you could specify the File name as data.file and the Directory as /ftp/public. Or, you could leave the Directory blank and specify the File name as /ftp/public/data.file.

Mode

This parameter is shown only for FTP or TFTP attachments. It lets you specify the transfer mode. For FTP the choices are:

• ASCII

• EBCDIC

• Image/Binary

For TFTP the choices are:

• NetASCII

• Octet

Server address

This parameter is shown only for mail server attachments. It lets you specify the e-mail address of the mail server. For example, majordomo@ishmail.com.

Subject

This parameter is shown only for mail server attachments. It lets you specify the subject line of the mail message to be sent to the mail server. Depending on how your mail server is configured, it may expect a command to be in the Subject field, the Body field, or both. An example command is: get /public/data.file.

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WARNING:
The sender is responsible for understanding how the mail server is configured and what commands it expects. This will vary among different organizations.

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Body

This parameter is shown only for mail server attachments. It lets you specify the body of the mail message to be sent to the mail server. Depending on how your mail server is configured, it may expect a command to be in the Subject field, the Body field, or both. An example command is: get /public/data.file.

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WARNING:
The sender is responsible for understanding how the mail server is configured and what commands it expects. This will vary among different organizations.

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Including a Message from the Active Folder

Including Your Signature File

When you click Signature -> a cascading menu is opened offering you the choice of four possible .signature files. See Signature Preferences for information about signature files. You can have different signatures for internal mail versus external mail. You can also have plain text and enriched text versions of the internal and external signatures.

Clicking this option places the contents of the .signature file at the cursor location.

Another way to add the contents of a .signature file to the composition is to click on the Append Signature button at the bottom of the Composition window. If you use this method, the signature is not appended until you send the message.