Since this afternoon, when I compose a new message and send it I get this error message and the mail remains in the Outgoing queue:
No se pudo transportar el mensaje. El contenido del mensaje no fue aceptado. Respuesta del servidor: 5.7.1 The message contains an unauthorized custom from address because the 5.7.1 associated account has been disabled or deleted. Please revalidate 5.7.1 the custom from if you believe this to be in error. ft6sm2837727wic.0 - gsmtp
This bug has only been reported for versions before 4.14, which have been unsupported for at least two years now. Can anyone tell if this bug still present?
If noone confirms this bug for a Framework-based version of kmail2 (version 5.0 or later, as part of KDE Applications 15.12 or later), it gets closed in about three months.
Just as announced in my last comment, I close this bug. If you encounter it again in a recent version (at least 5.0 aka 15.08), please open a new one unless it already exists. Thank you for all your input.