Limited time to send Email !!! LOOL

[rololo88]

Hello everyone, this is my first post which i had to start since after some search i didn't find the answer to my issue.
I use Thunderbird for several months now after migrating from Windows 7 to Linux. I think i may have found a bug
on my Thunderbird 38.5.1.

Here is the problem:

When i compose a new email it seems that i only have a limited time to send it otherwise if i wait too longtime
and leave it idle for sometime (dont know exactly how long) then i am simply unable to send the email.

It's very obvious when i have attached files or if i add image(s) in my message, Thunderbird shows "attaching ........"
forever and the message is never sent out.

Thank you in advance for your advices and sorry for my bad english

[DanRaisch]

Are you composing a completely new message or are you responding to a message you've received by replying to that message?