When I had reset issues I turned off email scanning in my anti virus. It was the cause of the problem.

Thanks for the advice Matt, but turns out it was already off. Didnt even know I had it. I might try the telstra site see if its a common thing with their mobile wifi function. it might be a time out thing or something.

thanks again for trying.

Funny, but all my resets were with Telstra ADSL. I do not see it with 3G connections. I went from timeouts to DNS failing to resolve and I have to click reload three times to load web pages when it happens. I wonder if it is just a dodgy Telstra thing.

Thanks Matt for taking the time to try and get to the bottom of my problem. Like i said its not a fatal problem i can still get my emails the long way round. I said mobile broadband i dont know if that's the wrong word, but our telstra thing is 4GX and our signal is 4G. Incredibly slow for fast... One thing i have noticed after living with this for a bit is, when i start the computer fresh (i rarely turn the laptop off) the yahoo works without resetting. So it may well be a dodgy telstra setting that cracks it if i leave thunderbird or just the computer on too long. Anyways thanks again for your input.

4g can be exceedingly fast, or really horrible. Living as I do halfway between the back of beyond and the black stump We have little choice. However several things have been observed "locally" with mobile data 3g and 4g. Both offer poor response when the school bus arrives in town and it does not get better until mid evening. This would indicate Telstra has some issues at least inherent to their service, backhaul might be the Achilles heal there.

Other issues I have seen include slowly degrading data throughput on windows 10 devices. Compare your phone and your laptop on similar tasks. This is quite often the result of anti virus products and scanning regimens that actually never end because they keep restarting.

While I have no been able to get to the bottom of what the issue are,

I have a feeling that Telstra, anti virus and IPV6 are not working as well as they should. I have seen evidence that certain US providers have not got their head around IPV6 resulting is DNS resolution delays while the IPV6 requests time out and then the IPV4 address is used. This exactly is not what is happening with Telstra, but I am seeing DNS resolution issues that lead me to think there might be issues with DNS and perhaps IPV6 resolution. Check the protocols installed on your network card in windows and disable IPV6 and see if things improve.

It is also possible that the cache of the common internet pages Telstra have maintained for around 20 years now is not performing to speed up requests like they think it is. Try modifying your DNS servers to 8.8.8.8 and 8.8.4.4 (Googles service just in case Telstra has issues with theirs.

I suspect that the meta data capture might be slowing services, but best of luck getting any sort of admissions or even facts about how that works in reality.

Then we get down to the other issue here. I suggest you try a different mail provider for some tests and see if it is a generic issue or just a poor service from Yahoo. I do know their mail service is fundamentally flawed and does a good job of messing up email formatting because they are sure the whole world only uses the US character set. They are really not a good mail provider anymore. It is basically their only function and they do not do it well.

Try creating an account with GMX.com for mail. It is very quick to create an account because they do not want to know what you had for breakfast. The service is standards compliant and it makes a great alternative to yahoo to see if the issue is mail in general or yahoo in particular.

I'm really sorry Matt, I feel I've waisted your time. I read and re-read your post but just don't understand most of it. I was just hoping for a setting in TB to say I use wi fi now, but I wasn't complaining about telstra, it just seems funny that on adsl we got about 2-5mbs and on wi fi we get 20-30mbs but youtube still buffers or whatever it is and weatherzone takes forever to load. Its possibly my computer that's messed up, anyway thanks for your efforts but I think maybe we should just let this one go. All the best.