This is a tough question because the answer depends on your audience and which email client they use. I build email newsletter for approx. 600 pixels based on past readings, and this topic recently came up again with a potential new client, so I decided to do a little research to see if this is still correct. Found a great article by Christopher Knight that looks into this question deeper and does some comparison (see below). I did some comparison of my own also of email newsletters that I receive (and did not create).
  • Westview Hospital’s Healthplex Sport Club: 818 pixels (centered)
  • Carnival Cruise Sale Promotion: 600 pixels (centered)
  • Dreamweaver Day Spa (Christmas special): 602 pixels (centered)
  • Netflix: 607 pixels (centered)
  • Bloomingdales: 760 pixels (centered)
  • Veer: 590 pixels (left-justified)
  • Kodak Gallery: 610 pixels (left-justified)
If you are looking for a quick answer, here is the sum of it:
  • Anything under 620 pixels is “safer” than anything greater than that.
  • If you want to play it safe, shoot for anywhere between 500 to 600 pixels for your HTML fixed width newsletter.
  • What you don’t want to do: Define an abnormally large width that will force your reader to horizontally scroll to read your email newsletter. This would be a big mistake.
Here’s the article: How wide should an HTML newsletter be?
… Now, the more popular “Defined Width” setting: Defined Width means that you specified a specific width that your email newsletter will be, regardless as to email client, monitor size or screen resolution. The majority of my newsletters are defined width around 620 total pixels wide.

Let’s look at some HTML ezines that I’ve received recently to see what they use for pixel width and whether they use left or center justification:
  • Andrea J. Lee in Creating What Matters uses 433 pixels wide (left justified)
  • Alexandria K. Brown, the EzineQueen uses 491 pixels wide (centered)
  • Sirius Satellite Radio uses 538 pixels wide (left-justified)
  • Christopher Guerriero of MaximizeYourMetabolism uses 557 pixels wide (centered)
  • Red Hot Copy (Lorrie Morgan-Ferrero) uses 595 pixels wide (centered)
  • Michael J. Katz’s E-Newsletter uses 595 pixels wide (centered)
  • Gary Ryan Blair’s The GoalsGuy Newsletter uses 628 pixels wide (centered)
  • eMarketer uses 790 pixels wide (centered)
Once you decide on the pixel size of width for your HTML email newsletter, the next decision is to LEFT justify or CENTER it. I left justify mine, but most folks CENTER them. Gut feel is that 70% of fixed width HTML newsletters are centered and 30% are left justified. This is personal preference.

What you don’t want to do: Define an abnormally large width that will force your reader to horizontally scroll to read your email newsletter. This would be a big mistake.

Analysis on the above sampling of HTML fixed width newsletters:
Anything under 620 pixels is “safer” than anything greater than that. eMarketer takes a great risk with their 790 pixel ezine width and they are really making a statement: Our readers are early adopters and the technologic elite who can afford and have the larger monitors and higher screen resolutions to view our email newsletter.

If you want to play it safe, shoot for anywhere between 500 to 600 pixels for your HTML fixed width newsletter.

If you are considering re-evaluating or starting a email newsletter campaign, consider TBH Creative for assistance with design and even selecting a vendor based on your needs. Thanks for reading and hope this was helpful.
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