how do I fix this?
For my email I use the program Thunderbird which is a Mozilla product. Before replacing my hard disk, to send email was fast and was automatically recorded in my ‘sent file’. Since I replaced by hard disk, Thunderbird has a new (?) but certainly bad feature in sending emails. It sends the email to the internet, but then in a separate function copies the sent email to the ‘sent" folder ‘which is a slow process and often I get an error message. So I do it again. When I look in the sent folder both copies are there., I haven't found a solution yet. The Help messages don't help and I haven't found a way to talk to someone at Thunderbird yet. I can not believe this is an intended feature or the program. If I do not find a resolution to this problem I will most probably drop Thunderbird.
Wšykne wótegrona (1)
Many email providers (Gmail is one) have a default setting which automatically places a copy of every sent mail in the Sent folder. Thunderbird also has this setting (in Account Settings > Copies & Folders). If Thunderbird is making a copy of every message you send and your email provider is doing it too, then you can experience the delay you mention and the duplication of copies in the Sent folder. The solution is to turn off one of the functions. In my Gmail setup, for example, Thunderbird is set not to save a copy of sent mail, but I get a copy in the Sent folder anyway because Gmail puts it there.