Internal Queueing Error - Email will not send

I am using Norton Internet Security (version 17.5.0.127) that came on a new HP Computer, purchased a couple of months ago, running Windows 7 Pro, 64 bit.  

 

Just this afternoon I started to get the following error when sending e-mail from my primary e-mail account:

 

451   4.2.0    Internal Queueing Error

 

The e-mail is not being sent.  I am able to send e-mail from my secondary e-mail account (a gmail.com address)

 

What's the problem?  Why did it just start and how do I fix it?

 

Thanks

I am using Norton Internet Security (version 17.5.0.127) that came on a new HP Computer, purchased a couple of months ago, running Windows 7 Pro, 64 bit.  

 

Just this afternoon I started to get the following error when sending e-mail from my primary e-mail account:

 

451   4.2.0    Internal Queueing Error

 

The e-mail is not being sent.  I am able to send e-mail from my secondary e-mail account (a gmail.com address)

 

What's the problem?  Why did it just start and how do I fix it?

 

Thanks