This is not really a bug but but a quite annoying feature. 1. Composing a mail as usual. 2. Selecting 'Send later via' Selecting one of the other mail accounts but default one as sender provides an error . The mail is routed to the selected provider giving error message. Message text: Failed to transport message. The server did not accept the sender address "uv.xy.in@gmail.com". The server responded: "5.7.1 <uv.xy.in@gmail.com>... You are using wrong SMTP server to send as uv.xy.in@gmail.com". The message is correct as the intended SMTP-address of my mail provider should have been used instead but has been replaced by kmail internally to use default smtp which is rejected by mail provider for obvious reasons. 3. Switching sender to the 'gmail.com Default Mail Account' and everything is as expected. The scheduled mail is send and received. 4. More over: Even in that case a message window shows up titled 'Error found - Send Later Agent' Displayed text: 'An error was found. Do you want to resend it?' There is no hint what error occurred. Just this message window. kmail version: Linux (x86_64) release 4.0.4-202.fc21.x86_64 compiler: cc Linux fedora 21 up to date system. Yes, I have read the bug reports quoted below. https://bugs.kde.org/show_bug.cgi?id=192046 https://bugs.kde.org/show_bug.cgi?id=261333 As far as I read the settings tabs everything is the way it should be and besides this 'send later' thing the accounts are in use for more than five years without errors using kontact. So, the question is, whether it is intended that the 'Send later' operates just via 'Default sender' or what went wrong during configuration. Thank you for your kind assistance.