the normal "mysql server gone" database error. so i meant addon was not working for me for unknown reason and i got lots of that db error in a second.

What were the specific errors you were getting?

i have stopped mysql service to check if i get 1 email only or attached by mysql server gone database error emails. i got tons of emails like usual .

I added this plugin and it seemed to stop all emails being sent from the site. I removed the code and the file and my site still is not sending any emails (error emails, user registration emails, etc). What can I do to fix this?

When I run the email diagnostics I get:

The mailing function returned an error while trying to send the mail.
The following errors were outputted by PHP when attempting to send mail:

Warning: 554 Unexpected response from SMTP server when ending transmission in ..../includes/class_mail.php on line 710

I don't see anything in this mod that could do that. My guess is that it's a coincidence of some kind. Did you try this mod because someone told you you were sending too much email? Maybe your host decided to do something about it on their end?

No, I added it to stop cut down on the error emails that come through when mysql goes down. I've switch to sendmail for now which is working.

Now what I can't figure out is I have it working with SMTP using my hosts' SMTP. But when I switch back to using Amazon SES which is what I used before I get that error.

Hmm...did you change the email address they are being sent to or from? Sometimes some servers will complain if the 'From' address isn't one they like. I guess there's no more information in the error message when you use the diagnostics?

That was exactly it. I switched from my domain email to my gmail account. Switched it back and it is working. Thanks.