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=3D in an email source is quoted-printable encoding for a literal equals sign (=). It is not a 3D HTML feature and has nothing to do with three-dimensional graphics. Decode the email body first, then read the resulting HTML.
How =3D changes back to normal HTML
Quoted-printable is a MIME content-transfer encoding used to carry email text safely. In that encoding, the ASCII equals sign is written as =3D.
For example, this encoded fragment:
xmlns=3D"http://www.w3.org/1999/xhtml"
content=3D"text/html; charset=3DUTF-8"decodes to ordinary HTML:
xmlns="http://www.w3.org/1999/xhtml"
content="text/html; charset=UTF-8"The first version is the transport-encoded email body; the second is the HTML syntax that the browser or mail client interprets.
What an equals sign at the end of a line means
Quoted-printable also uses a final equals sign as a soft line break. It tells the decoder that the physical line ended only because of wrapping and that the next line continues the same logical text. The break itself is removed during decoding.
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For instance:
href=3D"https://example.com/a-very-long-url=3D
and-more"
is joined at the line-ending marker before the remaining quoted-printable sequences are decoded. The result is one continuous value, not an intentional newline.
RFC 2045, section 6.7, states that an equals sign as the last character on an encoded line indicates a non-significant (“soft”) line break. The same specification limits quoted-printable encoded lines to 76 characters, which is why long HTML attributes and URLs may be wrapped.
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How to read or repair the source safely
- Identify the MIME body. Raw message source can include headers and one or more MIME parts. Work on the HTML part rather than changing the entire message indiscriminately.
- Join soft-wrapped lines. Where a line ends with a single
=, remove that terminal marker and join the next physical line. - Decode escape sequences. Convert hexadecimal quoted-printable forms such as
=3Dto their corresponding bytes;=3Dbecomes=. - Interpret the decoded HTML. After decoding, attributes should use normal assignments such as
class="..."andcontent="...".
Do not replace every equals sign in the source. An equals sign that is not part of a quoted-printable escape or a line-ending soft break may be genuine content, and changing it can corrupt the message.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Why your email client usually hides this
Email software normally decodes the MIME part before displaying the message, so recipients see rendered HTML rather than =3D. You are most likely to notice it when viewing “show original,” downloading a raw message, examining a mail archive, or opening an intermediate source file.
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Repair Windows errors before they cause bigger problemsFix Now →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →The presence of quoted-printable text alone does not establish which sender setting produced it. The excerpt that prompted this question shows an HTML message body but does not include all of its original headers.
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