Cannot send emails

[diana13]

What could be the reason that emails cannot be sent from time to time?

It happens once last saturday, and it happens again today.

 

I received some emails this morning, with new orders and out of stock products, now all emails stops.

 

My site was upgraded from 1.2.5 to 1.6.0.13, I suppose something went wrong regarding emails (test email gave me error all the time after upgrade), though emails works fine from sunday to friday.

 

If it's something from hosting, I don't even know what to ask.

 

Any idea?

 

PS: It works when I configure smtp with another gmail account, even the test email.

 

PS2. I've changed my gmail password, and now emails works again, except test email.

Edited May 2, 2015 by diana13 (see edit history)