After the update, I can no longer send emails using KMail. Emails I create are placed in the Outbox folder, but they aren’t sent from there. Even manually triggering the send process has no effect. Any ideas on how I can troubleshoot this issue?
Check your account (email provider) settings.
Try moving them to another mail folder and then sending them from there. In my experience, as long as there is still something sitting in the Outbox folder of kmail, it will block all other efforts to send.