imac apple mail 6.6 won't sometimes send
I am having trouble with Apple Mail 6.6.
A couple of times a day it won't send outgoing mail and of course it always happens when I'm in a hurry. The rest of the time it is working fine. I host my account at GoDaddy and they have confirmed that alll of my mail settings are correct.
POP Account, Outgoing mail server (SMTP) smtpout.secureserver.net: (my email address), Port 110 (confirmed with GoDaddy). "Use SSL" is unchecked (confirmed with GoDaddy).
The message I receive is:
"Cannot send message using the server smtpout.secureserver.net: (my email address). Sending the message content to the server failed. Select a different outgoing mail server from the list below or click Try Later to leave the message in your Outbox until it can be sent."
It gives me the option to check the connection status which show that both incoming and outgoing connections are successful.
I am using an iMac 3.4 GHz Intel Core i7.
Memory 16 GB 1600 MHz DDR3
OS X Version 10.8.5
Apple Mail Version 6.6
I appreciate any help. Let me know if any further information is required.
Thank you!
iMac (27-inch, Late 2012), OS X Mountain Lion (10.8.5)