It is possible that a mail message will not display as intended in some mail clients (either a desktop client such as Microsoft Outlook or a Web Browser such as Internet Explorer for web-based email). In order to make messages designed using FireMail have maximum compatibility, here are few guides:
Choosing the message type
Choosing the right message type involves, whether the message has to be a MIME based or RFC 822 based format. FireMail gives out two MIME message formats – PlainText and HTML; and one message format, namely UUEncoded for those that are based on RFC 822. Given below are the guidelines for choosing the required message format.- If the message generated is going to target clients on older Unix based systems, then UUEncodedMessage is a good choice. These messages will display properly even on newer clients and non-Unix based systems.
- If the message contains 8-bit characters, like extended ASCII characters, then it requires proper encoding for sending the message, so MIME-based is the only option.
- If a message contains only plain text (printable ASCII characters), then either UUEncoded or PlainText message can be used. UUEncoded is more efficient, but will not support extended ASCII characters and other character sets.
- HTML message is best if a message is targeted for both HTML readers and Plain Text readers. But it is necessary to provide both body (HTML) content and also the alternative (plain text) content.
- For creating a message with embedded images, HtmlMessage is the only choice.
Choosing the Character set
Choosing the right character set is required to ensure that the characters in the message are not altered in the client while displaying it. By default, FireMail assigns ISO-8859-1 for 7 & 8 bit characters and UTF-8 for Unicode characters. FireMail also supports others character sets in System.Text.Encoding.Choosing Image Embedding options
Embedding the images inside an HTML message can be done using the following methods:- Using Content ID (CID).
- Using Content Base and Content Location.
- Simply putting up the absolute URL in the HTML as the source path.
- For maximum compatibility, embed the image using the HtmlAttachment options and use the CID in the image source.
- For keeping the size of the mail to a minimum, use of an absolute URL of the image source as an option. With this option it is assumed that the receiver’s mail client can get the image from the external source every time the mail is viewed.
- It is possible to have a combination of embedded images and images pointing to an external source.
- If the HTML message contains the actual source of the image (rather than CID), then a combination of Content Base and Content Location at the message level should be used for best results. If the Content Base and Content Location are used, the images can be either embedded or external, and the HTML can be used without any alterations for the image source. For embedded images, the source of the image in the HTML and the Content Location of the HTMLAttachment must match.
- It is also noted that use of non-ASCII characters leads to encoding of the URL, which is not supported by some older clients.
| See Also |
Message Class | PlainTextMessage Class | HtmlMessage Class | UUEncodedMessage Class | Programming with FireMail for .NET