Email doesn't get opened in a browser per se (only in case of a webmail solution, or if the email clients fires up a browser).
So, you really should ask if all email clients will handle a gif file in a html encoded email message.
The answer is a very loud NO.
There are email clients that don't even decode html at all.
That said, most users aren't using those text only email clients anymore. But even those using email clients that parse html, the diversity of clients is significantly broader than with browsers, so don't expect anything near "perfect" everywhere.
Keep it simple! The fancier you try it to make, the more likely it's to blow up somewhere.
Some services that allow you to send out email to large lists have preview tools that allow you to see how commonly configured email clients will show your message. (There are probably others, I've only ever used mailchimp myself)
|Email doesn't get opened in a browser per se |
If my memory is correct, Outlook switched to using the rendering engine from MS Word instead of IE. That was an important security move from Microsoft.
However, today there are so many email clients that you have a huge spectrum to account for, not just a few "top" email clients. For example, just think about all the online email such as gmail, hotmail, etc. ANY browser might be used there, and they each have their own unique security steps for filtering any code included in the email. Then there are all the corporate and business email systems - it's immense.
|Outlook switched to using the rendering engine from MS Word instead of IE. That was an important security move from Microsoft. |
They switched, but I guess it was to make the editing with word they do in outlook to have it render more consistently for recipients that also use the same version of outlook. Works as expected inside a company if all are on the same versions.
As far as security goes: letting word handle html from random sources ... it's not really written with security in mind from the start way back when they first made word.
And the horrendous html word creates ... yuck.
Don't put ANYTHING important in an image. Many-or-even-most recipients will never see it. Don't know about the rest of youse, but I can just about count on the fingers of one hand the number of times I have ever clicked the e-mail reader's "load images" button.
Images that are sent along with the email are loaded more readily by visitors than images than are pulled from web servers.
But even then: just make sure to always include a text only version of the email, and provide a link in the html version at the very top "if you can't see this email properly, click here" that points to a web server showing the same info.
There is a matrix of support by various email clients at:
I keep Yahoo, Gmail, and AOL email accounts open so I can test them to make sure my order and shipping confirmation emails are making it thru. Anyway, one or two or all of them don't display images, by default. (I lost track of which ones as I changed the defaults to show images. I'm pretty sure I had to do that twice.) From my exerience, most users aren't so swift when it comes to changing default settings.