Is this a new installation? Has this suddenly happened? Down Detector is showing that there are connectivity problems with Optusnet in Australia at the current time. How long has this been continuing?

Its not a new installation.. Been happening for about 4 days.. Had optus on the phone for 4 hours and couldn't resolve the issue. I can see my email on optus webmail so seems to be a send/receive issue between Optus server and Mozilla Thunderbolt. ???

It's not just receiving, then? You said in your latest email that you can't send. Did Optus give you any indication why their server is refusing the connection? Did they blame a setting or a password or a port setting, for example?

Hi, I'm with Optus too and have just started having the same problem in last 5 days, cant send or receive emails and getting the same error, not a new installation either.

Hi, I'm with Optus too and have just started having the same problem in last 5 days, cant send or receive emails and getting the same error, not a new installation either.

Hi, WWT,

I help out here with preliminary gathering of info clarification and answer a few of the more straightforward queries (which often turn out not to be straightforward at all)...

...this theme of sudden loss of connectivity is quite common (although, when you think about the total amount of users, it's actually very small).

I can't help on this except to say that many of the problems with connectivity are due to Third Party software - especially BitDefender - that manifest themselves in various error messages. If you search for similar problems in the search bar, you'll find a lot of suggestions from the forum users.

See also - https://support.mozilla.org/en-US/questions/1486768#answer-1704464 (three Optus users with the same problem all within 24 hours).

Thanks for the reply frisee, i don't have Bitdefender and haven't changed anything with my internet security software or 3rd party software so its a mystery, Ive been really enjoying Thunderbird, its a great program so this is a bummer but will look online some more to try and find a solution, thanks very much.

okay - I finally got to the root of the problem. It turns out as of the time my email problem first started that Optus was no longer supporting Thunderbird. After a very prolonged discussion and pointing out that I have been a customer for almost 30 years and pointed out the time I had wasted trying to resolve this problem, they agreed to have there tech team have a look at it ....long story short - they have re-established my connection so I am still able to use Thunderbird....not ideal ...but problem solved for me at least. Thanks for all the support and input.

Thanks likeoom for having the patience to deal with them. I've been thinking of changing my isp, this will probably hasten that decision. Pity. But thanks to all anyway.