[thelist] Optimum HTML size

Volkan Özçelik volkan.ozcelik at gmail.com
Thu Feb 28 23:48:41 CST 2008


Related to the topic:

A few months ago I was trying to increased the e-mail delivery rate of a
very large business network (which sends around 1 million+ e-mails per week
included weekly bulletin messages, system messages, activity notifications

The site was issuing delivery problems for major e-mail providers (like
Yahoo! and Hotmail). Especially Yahoo! was almost strictly rejecting the
e-mails and putting them to spam/bulk folder.

Here are my findings that might help:

- Needless to say, you should have properly opted (preferably double opted)
list of correspondents.
That is to say you sould not send unwanted e-mails to anyone for any means.

- Get a SPF record -- an SPF record is easy to setup, also register for
DomainKeys if possible.

- If you experience an unexpectedly low delivery rate, contact to the
providers (like Yahoo! and Hotmail) directly
<hint>If you know an insider, this will speed up the process; if not, most
of the providers ask some sort of a questionaire to fill in,
fill the questionare truthfully and **honestly** BUT keep in mind what these
providers expect from you to write in that questionaire.
That is, don't lie to them, but think very well on what to say</hint>

- Yahoo! likes strictly well-formed HTML in the e-mails -- which I am not
surprised.  Don't put garbage markup to mails you send to Yahoo!

- Hotmail PREFERS garbage markup in the e-mail  -- which I am not surprised
I've observed that, when we modify the markup as it was composed in M$
Outlook (with a lot of unneccessary M$-specific classnames, tags, nested
fonts and spam), the mails went straight into the inbox of our test Hotmail
account. Whereas sending a plain-jane clean XHTML markup found itself in
bulk :) -- Please note that this may not be applicable to you. Just keep in

- Corrollary to the point above, prepare seperate e-mails for different
e-mail providers for high success.

- Some providers prefer text-based e-mail to all others. So make sure to
provide a textual alternative to your HTML e-mail. This is done by sending a
content-type and let the e-mail provider decide on what to choose.

- If you experience low delivery rates, keep in mind that, sometimes
text-based e-mail is the only option for some providers.

- Before sending any e-mail, test them in newly created test accounts in
Hotmail, Yahoo! etc. Make sure that they no not go to junk/bulk.

- (this VERY is important) Have a proper bounceback policy for soft (4xx)
and hard (5xx) type bounces. Preferably do not send any further e-mail to
hard bounces and retry soft bounces for 3 times before blacklisting.

- Periodically monitor your delivery and success rates. If anything unusual
happens, return to step 1.

By following the above guidelines we managed to increase the delivery rate
from around 20% to around 90%+, which is a big leap.

Hope that helps,
Volkan Ozcelik
+> linkibol.com - in seek for quality links : http://www.linkibol.com/
+> Going solo in Turkish: http://www.fikribol.com/donkisot/
+> My projects/studies/trials/errors : http://www.sarmal.com/
+> Sardalya JavaScript Library: http://www.sarmal.com/sardalya/

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