Gmail's new image caching is breaking image links in newsletter

Question 1

I think I have figured out the GoogleImageProxy issue.

This is something related to CACHING concept. suppose, you have recently deployed your PHP code on your server but you forgot to upload images. you tested once with your email logic. your system generated an HTML email. When this email will hit the Gmail server GoogleImageProxy will try to fetch and store the images from your site on its own proxy server. while fetching the images, GoogleImageProxy found some 404 statuses against your missing images and 403 against some protected images. GoogleImagesProxy has stored these statuses into its own proxy server.

Now tried to open your email, and you noticed some 404 statuses against your images. This is something understandable. You immediately realized that you forgot to upload some images, so you uploaded them to your server. and also you have fixed some permissions against protected images.

You are all done now. Now you try to run your PHP-email script once again. As a result, you receive another email in your Gmail or Hotmail inbox. you had fixed all the issues with your images. Now the images must be displayed in your email content. but you are still unable to see the images.

Ah, possibly you forgot to clear your browser's cache. Clear your browser's cache and load the Gmail or Hotmail page once again. But the result will be still the same. Try to apply dozens of fixes/patches and try to run your PHP-email script a thousand times. But the result will be still the same. No improvement.

THE REAL PROBLEM

What the hell is going on? Let me explain it to you. Go to your access log and try to find requests from GoogleImageProxy. You'll be surprised to see that there will be only 2 or 3 three requests from GoogleImageProxy depending on the number of different images used in your email. GoogleImageProxy never tried to fetch images Even after you have fixed the issues with your images by uploading missing images and setting permissions for protected images. Why? Clearing your browser's cache has no impact. GoogleImageProxy will never fetch the fresh images even for your newer email because the images are now cached into GoogleImageProxy along with their last status code and not cached in your own browser.

GoogleImageProxy has set its own expiry date for the images. I think one month. so now the fresh copy of images will be fetched after the expiry date. I mean after one month. You can not force GoogleImageProxy to fetch the images. But it is important for you to display images in your email. What can be the solution?

THE SOLUTION

Following is the only way to force GoogleImageProxy to fetch your images

Rename your images to something else with png, jpg, or gif extensions only.
Don't use any kind of query string in your image URL like ?t=34343
your image must include png, jpg, or gif as an extension.
your image URL must be mapped onto your image directly.
If you need to use some proxy URL for your protected images then your response must include the proper header like Content-Type: image/jpeg
File extension and content-type header must match
Status-code must be 200 instead of 403, 500, etc

IMPORTANT NOTE

Try to repeat the whole process for every run of PHP-email script. because every time GoogleImageProxy will cache your images and you'll have to repeat the same process for every new try.

Hopefully this will fix the issue for most of the people.

Question 2

Based on your example, it looks like you are using traditional extensions (.jpg, .png, .gif). Some folks on this thread, describing the same issues you are facing, have stated that using those extensions solves the problem.

Other possible solutions:

Image links broken in Gmail because of google's Image proxy
Doubtful, but maybe a cookie problem
Image URL proxy whitelist setting - this has turned out to be the solution for a few users who are under Google Apps. Via Gmail is not showing image when image url is getting appended with https://ci4.googleusercontent.com/proxy

Question 3

I was having a similar issue, but it was caused by the length of the URL. Google generates the following URL when caching an image from gmail:

https://ci4.googleusercontent.com/proxy/[hash]#[url])

The hash generated is based on the URL of the image, but the size will vary based on characters used. I ran several tests with different sized URLs, and found the cached image would fail to load consistently (400/Invalid Request) if the hash exceeds 2076 characters in length (close to 2048 bytes + meta? not sure).

Again, the image URL could generate a hash that exceeds this many characters at ~1000 special characters, or 1500+ simple characters. If the hash exceeds 2076 characters in length, the request fails.

I realize this is an old post, but hopefully this helps other devs scouring Google

Question 4

I know this is an old question but the same thing happened to me. When I checked my access logs this is what I found -

www.example.ca 66.249.85.50 - - [10/Apr/2014:17:57:18 -0400] "GET /newsletters/Apr10_2014/cad/cad2.jpg HTTP/1.1" 403 457 "-" "Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.0.7) Gecko/2009021910 Firefox/3.0.7 (via ggpht.com GoogleImageProxy)"

You can see that my server was blocking the GOOGLEIMAGEPROXY giving it a 403 Forbidden reply. I decided to check my .htaccess and sure enough I was blocking the term PROXY. After removing the term, the images appear just fine now on Gmail. Hope that helps.

Question 5

I just tried , after replacing the image (without changing image name)

Open email in new browser , it shows new image
Ctrl+f5 (forces a cache refresh) in the chrome (my default browser) , also shows new image

Question 6

use .png or .jpg 
otherwise image will not render

url add auto https://ci3.googleusercontent.com/proxy/jTpYlM6RUv7Wi8Hxjha4fzExKFy9mjyh133MKKfo3FuV3toLToG6zJcA0IAdIMEW75pY6pkEd2aOSVhWIn0A82q-24YaAd-_k00wIMHwIuUBiy9vEGrMpAW73HaHQmViuESP7A=s0-d-e1-ft#

Question 7

HTTPS image locations do cache. Several of our production environments have no problems with gmail proxying image locations using a HTTPS uri. I could see gmail ignoring your content if the SSL certificate is invalid in some way.

Question 8

Check that the content-type returned for the image file by your server is correct.

You can check this using Fiddler.

Question 9

In my case the size of file was the problem, it was 22 Mb (i know right?), and after we reduced the size everything started working like a charm.

Check file size and if it's too big, compress it.

Question 10

I know this is an old question but I've met this problem. In my case images are stored at Google Cloud Storage. What is interesting is that link

https://storage.cloud.google.com/{bla_bla}/logo.png

returns 307 (temporary redirect) and Location header containing something like

https://{xxx}-apidata.googleusercontent.com/{bla-bla_bla}/logo.png?{zzz}

Seems like GoogleImageProxy does not process 307 correctly

Question 11

I have a perfect solution of this problem, which worked for me if you are using PHPMailer then you just have to add another option in PHPMailer for attaching image like this

$mail = new PHPMailer(); $mail->AddEmbeddedImage('../absolutepath/image/image.jpg', 'logoimg', '../absolutepath/image/image.jpg');

Here we have given absolute path of image and give it a name call 'logoimg' or whatever you want.

Now you can add this logoimg to wherever in your HTML Body like this

$mail->Body = " <h1>Test of PHPMailer html body with image</h1> <p>This is a test picture: <img src=\"cid:logoimg\" /></p>"; $mail->send();

That's All.

Question 12

I had this issue when I was sending gifs. I found that the file size matters to Googles Proxy server. I suggest making the files as small as possible and see if that works. You can use your Gmail account and add a photo from a URL to test. If the gif shows up when you are composing your email it will be receivable.

happy coding.

Question 13

Is it working from Outook/hotmail? It should then we can isolate it as google issue. In your case it is not.
Size of the image can be a problem. Try to reduce it and see
www.mysite.com this site might be accessible from your system. But is it also accessible from google server?
Try changing extension.. this is the trick: You might have tried several things but it would still fetch from cache(which invalidates your efforts) but when the extension changes, it fetches again and all the work you did before comes into play and if it works you might think it is the 'extension' that did the trick!! (like many of those who speaks about extensions)

Question 14

In my case of running into this issue, the problem was that accidentally the path to the image in the email template had triple slashes in the URL, e.g. https:///content.example.org/image.png. This was hard to spot, and while it was working in other email clients who could successfully resolve the URL, Google's image proxy wasn't able to handle it and resulted in a 404 for the proxied image address.

Question 15

Make sure that Gmail is request your image over http, not https.

Lets say your normal image url is:

https://www.mysite.com/images/pic1.jpg

So change to:

http://www.mysite.com/images/pic1.jpg

I have a strong feeling that google's proxy don't cache https.

Question 16

It's March 6 and you've probably already figured this out, but thought I'd chime in to help others. I discovered that JPGs don't work in gmail. The PNG format works great. Sorry I can't explain why, but sometimes it's better not to ask why. Use PNG!