Email Campaign Not Sending

[Portia]

When I set a new email campaign to active, with plenty of target lists and a mass email with its status set to "pending", it's not sending to anyone.
In the log, where it usually shows the addresses that are pending, all it shows is my email, from where I have clicked on the links to test them.
Not sure what else to try. Any suggestions?

[yuri]

Can be a cron not set up.