Cox Mail Not Sending from Email Clients

Hi,

I've been using my cox email account to receive and send email from both Outlook 2010 software on my Windows PC and the mail client on my iPhone for a long time, but recently I stopped being able to send (I could always send before). Whenever I send something now, it shows it being sent and is then put in the Sent mail folder, but it never arrives in the destination mailbox. I also never receive any kind of error messages. I've tested it over and over from both Outlook on my PC and iPhone by trying to send both to my own account as well as my wife's. I use all of the recommended settings:

Incoming: imap.cox.net port: 993 (I was using the pop server on my iPhone before, but it stopped working, so I switched to IMAP, but it still doesn't work)

Outgoing: smtp.cox.net port: 587 with SSL (I've also tried 465)

I finally tried logging on to cox webmail and successfully sent from there, but that's not really a super convenient solution.

I've done some searching around on forums and found similar issues, but nothing that was really helpful. Please let me know if anyone has any ideas about this. I'm really stuck.