The PC version of thunderbird does not time out while retrieving email, but the portable version does.
Another user had reported the same problem.
(https://portableapps.com/node/14008)
This problem occurs not just on my machine or my network but for several of my friends and other networks. So it has to do with thunderbird portable.
I did some search and found that there is a way to increase connection time out time, but this is not available in the portable version.
I find the app very useful and so on many, however the frequent time out makes this application very difficult to use. Would be really nice if this time out problem is addressed AND also the option to change the time out value that exists in the PC version, also be added to the PORTABLE version.
NO REPLY !!! HOPE THERE IS A RESPONSE OR HELP ON THIS
Sorry portableuser1 not a dev so cant help too much with the core of your issue but for a temporary workaround you can change the timeout setting from
Tools>Option>Advance Tab>Connection Timeout
Now this may not solve your issue but increasin this may help with your problem. It is also possible that the problem is with your email provider or the if the network your on uses a proxy. I suggest moderating your above comment to normal case so as not be yelling at those who can be more helpful and they'll be more likely to drop in and solve your problem for you.
Good luck.
PortableApps.com Advocate