If it is not there, sending or drafting mails fails with "could not save" or similar. /home/kardan/.claws-mail/tmp/queue.0x962a2207a139acd: fopen: file not found /home/kardan/.claws-mail/tmp/queue.0x955ea6868f4a1ae: fopen: file not found /home/kardan/.claws-mail/tmp/draft.0x955ea68: fopen: file not found
The tmp directory is created on start-up if it does not exist. Perhaps you removed it manually while Claws was running?