Yes, have her try to send any large image in a separate file. The issue with attachment size is a cumulative issue. In other words, it may be related to the combined size of the images, not the size of a single image. It is possible. that when a threshold level for total attachments is reached, the compression become more aggressive.

We have seen things like this with AOL in the past. Unless AOL user turn off the compression, the images viewed on web sites are further compressed as they pass through the AOL servers and many become distorted because of this. This can make some web sites look pretty crappy.

If your aunt is using AOL for her ISP, they could be compressing e-mails in a similar manner, although I do not know exactly what AOL is doing with their e-mail messages.

There does not seem to be any rhyme or reason behind why some open and some don’t. For example in December an email was received that had a 117k photo and a 70k photo that would not open in Thunderbird (but opened just fine directly in gmail). 1 week later my aunt sent an email with three 100K plus photos and Thunderbird opened them up just fine.
This really has me scratching my head as in the end I am getting funny looks since I am the one who moved her over to gmail and Thunderbird from a very irritating roadrunner account.

Thanks,

Tom

FWIW, other than Windows 7 putting the Thunderbird data in a different hidden folder:
C:\Users\\AppData\Roaming\Thunderbird etc.
everything else seemed to set up exactly like Windows XP.

Thanks for your help.

Read the article about Changing the Thunderbird File Location with XP. The article explains where you will find the email files, how to move them to a new location and how to connect Thunderbird to the new location. It is always a good idea to keep all important files in a location that is easy to back up.

There actually is no such thing as a decompression for JPEGs, unless it uses a separate method, such as with zip file compression. Once a JPEG is compressed using standard JPEG compression, it stays compressed forever.

As far as I know, Thunderbird does not compress attached images, but it does encode attachments as part of the message. In other words, when an e-mail attachment is sent, it is stored in Thunderbird as part of the e-mail. There is no separate file for the attachment. That may be where you are running into problems if there is something wrong with the JPEG format and Thunderbird cannot interpret it.

You might want to see what type of tool your aunt is using to send the images. They should be sent as attachments and not embedded, especially if they are large files. it sounds like they are attachments.

It looks like there is a 25 meg limit for GMail attachments.

http://mail.google.com/support/bin/answer.py?hl=en&answer=8770

You will find the following on that page.

“With Gmail, you can send and receive messages up to 25 megabytes (MB) in size. Please note that you may not be able to send larger attachments to contacts who use other email services with smaller attachment limits.”

It could be that GMail is compressing the large files using a proprietary method that they can interpret, but Thunderbird cannot. I suspect that the problem is with GMail.

Your aunt’s ISP could also be part of the problem if they are doing something to limit attachment sizes. You probably have at least two different ISPs and GMail involved in this.

You might want to have your aunt try to send each large JPEG file attached to a separate e-mail message to see if that works. That might avoid any GMail filter that could be compressing the larger images if the total size of the attachments exceeds their limit.

Have you seen this problem with anything other than a GMail account? That could tell you if GMail is causing the problem.

Perhaps someone else has a solution for this. Feel free to join in if you have a solution.

The real problem is all of the variations with e-mail formats, forwarded messages versus original messages, etc. Some of the messages may have embedded images, which are controlled by the sender. If the image is not embedded at the source, it will not be embedded when you receive it. “Inline” merely tries to force attached images or documents to display after the message.

The problem is likely related to the way the messages are being sent.