Question

I receive email messages over sockets and see that long lines in the message body are broken up, separated by the following expression

'=\r\n'

I cannot find any documentation on this and wonder if someone just happens to know where I can find information on this behavior.

Also, please ONLY feedback on my question, no comments regarding email and sockets!

Thanks
Alex

Answer 1

From Wikipedia, regarding Quoted-printable:

Lines of quoted-printable encoded data must not be longer than 76 characters. To satisfy this requirement without altering the encoded text, soft line breaks may be added as desired. A soft line break consists of an “=” at the end of an encoded line, and does not appear as a line break in the decoded text.

The \r\n is likely coming from whatever is generating the content or body of the email, and is a line break also. Depending on the client used to view the message, it may or may not render as an actual line break.