Avoid uploading email twice when using an IMAP client


Would it be possible to save sent email to the sent folder without having to re upload the email to the sent folder?

I use Thunderbird but I guess this would be the same for every IMAP client. When I send an email it sends it to the recipient via SMTP then re-uploads it to the sent folder via IMAP. If the email has attachments this can take a long time. With my internet connection, a very long time…

With Roundcube this is all handled on the server so is quick. I guess the solution would be to configure the SMTP service to save all messages to the sent folder?