Hi austincotton, Thank you for your question. I understand that:

Hostgator -send email via Thunderbird -> yahoo bad new, it freezes and hangs in Firefox and cannot open message Hostgator- send email via Thunderbird -> yahoo good old

In the composition preferences of the Hostgator account in Thunderbird are there any special formatting or Addressing that may be affecting the composiotn of the email?

If you open up the original or txt view of the email, does it look different from the sent copy in the hostgator account and the yahoo inbox (besides the headers)?

Ah and the behavior that you are experiencing is Bug 996013 - Yahoo! Mail breaks in Versions 20 and below due to lack of window.location.origin which looks like they are working on a fix for the new Yahoo.

Support, sounds like a possible reason....how did you find the issue....I've tried searching the web for a possible resolution or answer?

Secondly, been using my webmail because of the issue using the email client when sending email messages to a yahoo account. Was almost positive it worked using the webmail to yahoo. However, it results in the same issue....cannot open a message in yahoo sent from my hostgator webmail.

According to my contact that uses the yahoo webmail....."I'm the only customer he has ever delt with that email messages cannot be opened.

Let me know what I can do to fix this.....is there a way to contact yahoo directly for this kind of issue. I've triend multiple times to find a way to contact yahoo directly.

Thanks, Kris

Your missing the point. The issue is Firefox versions less than 20. Not Thunderbird.

Advise your correspondent to update their version of Firefox to something later than 20. Given the current version of the software is 28 I think it is not to much to ask.

Support, sorry you might be confused because I am using Chrome v32 on Mac OS 10.7.5.