Been investigating SMTP send failures and providing users with better feedback should a message fail to be sent from tiggit mail.
Made a couple of changes. The first is obvious: adding a check when the message is sent that the server sends back a status if 250 to show the mesage has been sent, and tell the user if the message fails.
The second is just implementing the send now logic properly. When selecting send now, tiggit mail used to just send the message optimistically. If it failed to go, then it just got lost. Now it copies the message to the outbox, and then causes the outbox to start sending. This means that should messages fail, then they are held in the outbox until the next message is sent, or sending is started. This may remove the need for send now and send later, but user feedback on this i guess is needed.
Version 0.1.48 of tiggit mail may make it out this weekend.