On Fri, 12 Oct 2001 02:32:18 Syd Hancock wrote:
Hi all Still battling with the basics.
Do my posts appear with =20 line ends (can't remember if these represent CR or LF)? Apparently they do for some list readers.
Neither - =20 actually stands for a space character in the encoding scheme called quoted-printable and is normally seen when a paragraph has been wrapped automatically my the mail software.
The way these get introduced is like this:
Take a paragraph with spaces between the words and then insert newline characters to word wrap at a specified width. If you insert the newline characters rather than replacing one of the spaces with a newline then it remains to decide what happens to the space. Normally the newline will be inserted just after the space, so the first line with finish with a space rather than the second line start with one.
Now, when the mail software (MUA to be specific) goes to send the messages it realises that SMTP makes no guarantee to preserve trailing spaces on lines so in order to preserve them the mail software has to encode the message and chooses the quoted-printable encoding in which characters that need protection are converted into a equals sign followed by the two hex digits of the character's code, so =20 represents the character 20 hex (32 decimal) which is space.
When the mail is received the mail reader program should see that the message is encoded and reverse the coding before displaying the message to the user. If this does not happen it can be for a number of reasons:
1. The receiving mail program doesn't understand the MIME header which gives the encoding type or doesn't implement the decoder for quoted printable.
2. The mail sending program failed to include missed the MIME header which gives the encoding type, or got the syntax wrong.
3. A program along the route, whether a simple mail transfer agent (MTA) or a mailing list manager had dropped the header without itself undoing the coding.
The test, then, is to send messages to some test addresses and then read them with a mail reader that can confirn if the header concerned is still there. IIRC the header you are looking for is Content-Transfer-Encoding or some similar name.
As for the line length to begin with, 78 is fine for an original message but gives no scope to indent that message when someone wants to reply to it - 65 to 70 is a better choice.
Steve.