Store is suddenly not mailing order confirmations

My ZenCart v.1.5.1 is suddenly not mailing order confirmations. I am not getting the order confirmation copies I used to get, and the customer is also not receiving confirmation emails (I verified this by placing a test order myself). Orders are showing up in the cart and everything else seems okay, but emails are not happening.

I did not change any settings recently. These are my Configuration -> Email Options:

E-Mail Transport Method PHP
E-Mail Linefeeds LF
Use MIME HTML When Sending Emails false
Send E-Mails true
Email Archiving Active? false
E-Mail Friendly-Errors true
Email Address (Displayed to Contact you) [email protected]
Email Address (sent FROM) [email protected]
Emails must send from known domain? Yes
Email Admin Format? TEXT
Send Copy of Order Confirmation Emails To [email protected]
Send Copy of Create Account Emails To - Status 0
Send Copy of Create Account Emails To [email protected]
Send Copy of Customer GV Send Emails To - Status 0
Send Copy of Customer GV Send Emails To [email protected]
Send Copy of Admin GV Mail Emails To - Status 0
Send Copy of Customer Admin GV Mail Emails To [email protected]
Send Copy of Admin Discount Coupon Mail Emails To - Status 0
Send Copy of Customer Admin Discount Coupon Mail Emails To [email protected]
Send Copy of Admin Orders Status Emails To - Status 0
Send Copy of Admin Orders Status Emails To [email protected]
Send Notice of Pending Reviews Emails To - Status 0
Send Notice of Pending Reviews Emails To [email protected]
Set "Contact Us" Email Dropdown List
Contact Us - Show Store Name and Address 1
Send Low Stock Emails 0
Send Low Stock Emails To [email protected]
Display "Newsletter Unsubscribe" Link? true
Audience-Select Count Display true
SMTP Email Account Mailbox YourEmailAccountNameHere
SMTP Email Account Password ****************
SMTP Email Mail Host mail.EnterYourDomain.com
SMTP Email Mail Server Port 25
Convert currencies for Text emails

Any help would be much appreciated!

UPDATE - well, that's weird! I have just this minute received back-copies of all missing emails, going all the way back to this morning.
So I guess there was a temporary glitch somewhere that has resolved itself. ??!
All's well that ends well. :smile:

Just to be clear
This was NOT a problem with zen-cart as it was sending the emails.
After they are sent, its up to your mail server to send them out.
So the glitch was probably a problem with the mail server