[development] HTML emails

Steven Peck sepeck at gmail.com
Thu Jul 17 20:00:30 UTC 2008

On Wed, Jul 16, 2008 at 6:59 PM, Larry Garfield <larry at garfieldtech.com> wrote:
> On Wednesday 16 July 2008 4:26:38 pm Benjamin Lewis wrote:
>> Eric-Alexander Schaefer wrote:
>> > Larry Garfield schrieb:
>> >> I am going to take the luddite position.  Consider yourself warned. :-)
>> >
>> > Thanks (for your position, not the warning).
>> > Plaintext should be the default and HTML _could_ be an option. If HTML
>> > is used, it should contain a plaintext version.
>> It MUST contain a plaintext version (per RFC 2119 [1])
>> [1] http://tools.ietf.org/html/rfc2119
> You're making the naive assumption that people actually follow that
> requirement. :-)  LOTS of email floating about the Net, both legit and
> spam/trojans, contains HTML and no body.  And sending the message twice
> (plain and HTML) is a slap in the face to anyone on low bandwidth.
> --
> Larry Garfield
> larry at garfieldtech.com

Urban legends aside, actually it is not a naive assumption, it's a
valid one and the referenced RFC is a good starting point for anyone
wanting to develop a valid message format.  The vast majority of spam
filters will in fact block as spam malformed messages.  A message is
considered malformed if it only has HTML content and no text
component.  The percentage in gross terms of malformed messages
(particularly deliberate spam) is fairly low to the overall percentage
of email.  We block approximately 85-90% of the incoming email where I
work as spam and of that 85-90% less than 2% is triggered as
malformed.  It is a mid-sized environment with about 30 million
messages in the last month.  In the early days of spam (where simple
word filters roamed free as the tool of choice), malformed messages
were not tested for and as a result spammers used that technique for a

While sending HTML messages is in fact harder on low bandwidth
recipients, HTML messages are a fact of life and there is a portion of
a given customer base that does in fact want to use it.

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