From the Project/Properties menu, click on the Mailer tab:
Select the Save sent messages option: no, header only, yes. If No is selected,
resuming of aborted render won't be available.
Select the Save aborted messages option: no, header only, yes. If No is selected, aborting all outbox messages will delete them. Otherwise the full message or just the header will be transferred to the 'aborted' folder. Note that messages which addresses cannot be resolved will also be transferred accordingly.
Select a Throttle value: determines the overall maximum quantity of messages sent per minute, regardless of the number of outgoing queues and their respective thread count settings.
Retries: sets the interval between connections attempts to the receiving mail server.
