email.errors: Exception and Defect classes¶
Source code: Lib/email/errors.py
The following exception classes are defined in the email.errors module:
-
exception email.errors.MessageError¶
This is the base class for all exceptions that the email package can
raise. It is derived from the standard Exception class and defines no
additional methods.
-
exception email.errors.MessageParseError¶
This is the base class for exceptions raised by the
Parser class. It is derived from
MessageError. This class is also used internally by the parser used
by headerregistry.
-
exception email.errors.HeaderParseError¶
Raised under some error conditions when parsing the RFC 5322 headers of a
message, this class is derived from MessageParseError. The
set_boundary() method will raise this
error if the content type is unknown when the method is called.
Header may raise this error for certain base64
decoding errors, and when an attempt is made to create a header that appears
to contain an embedded header (that is, there is what is supposed to be a
continuation line that has no leading whitespace and looks like a header).
-
exception email.errors.BoundaryError¶
Deprecated and no longer used.
-
exception email.errors.MultipartConversionError¶
Raised if the attach() method is called
on an instance of a class derived from
MIMENonMultipart (e.g.
MIMEImage).
MultipartConversionError multiply
inherits from MessageError and the built-in TypeError.
-
exception email.errors.HeaderWriteError¶
Raised when an error occurs when the generator outputs
headers.
-
exception email.errors.MessageDefect¶
This is the base class for all defects found when parsing email messages.
It is derived from ValueError.
-
exception email.errors.HeaderDefect¶
This is the base class for all defects found when parsing email headers.
It is derived from MessageDefect.
Here is the list of the defects that the FeedParser
can find while parsing messages. Note that the defects are added to the message
where the problem was found, so for example, if a message nested inside a
multipart/alternative had a malformed header, that nested message
object would have a defect, but the containing messages would not.
All defect classes are subclassed from email.errors.MessageDefect.
-
exception email.errors.NoBoundaryInMultipartDefect¶
A message claimed to be a multipart, but had no boundary
parameter.
-
exception email.errors.StartBoundaryNotFoundDefect¶
The start boundary claimed in the Content-Type header was
never found.
-
exception email.errors.CloseBoundaryNotFoundDefect¶
A start boundary was found, but no corresponding close boundary was ever
found.
-
exception email.errors.FirstHeaderLineIsContinuationDefect¶
The message had a continuation line as its first header line.
-
exception email.errors.MisplacedEnvelopeHeaderDefect¶
A “Unix From” header was found in the middle of a header block.
-
exception email.errors.MissingHeaderBodySeparatorDefect¶
A line was found while parsing headers that had no leading white space but
contained no ‘:’. Parsing continues assuming that the line represents the
first line of the body.
-
exception email.errors.MalformedHeaderDefect¶
A header was found that was missing a colon, or was otherwise malformed.
Deprecated since version 3.3: This defect has not been used for several Python versions.
-
exception email.errors.MultipartInvariantViolationDefect¶
A message claimed to be a multipart, but no subparts were found.
Note that when a message has this defect, its
is_multipart() method may return False
even though its content type claims to be multipart.
-
exception email.errors.InvalidBase64PaddingDefect¶
When decoding a block of base64 encoded bytes, the padding was not correct.
Enough padding is added to perform the decode, but the resulting decoded
bytes may be invalid.
-
exception email.errors.InvalidBase64CharactersDefect¶
When decoding a block of base64 encoded bytes, characters outside the base64
alphabet were encountered. The characters are ignored, but the resulting
decoded bytes may be invalid.
-
exception email.errors.InvalidBase64LengthDefect¶
When decoding a block of base64 encoded bytes, the number of non-padding
base64 characters was invalid (1 more than a multiple of 4). The encoded
block was kept as-is.
-
exception email.errors.InvalidDateDefect¶
When decoding an invalid or unparsable date field. The original value is
kept as-is.
©
Copyright 2001 Python Software Foundation.
This page is licensed under the Python Software Foundation License Version 2.
Examples, recipes, and other code in the documentation are additionally licensed under the Zero Clause BSD License.
See
History and License for more information.
The Python Software Foundation is a non-profit corporation.
Please donate.
Last updated on Nov 12, 2026 (16:37 UTC).
Found a bug?
Created using
Sphinx 9.1.1.