I'm using magento 1.7.2 all patched...
Also i'm using Aschroder smtp pro.
Suddenly my confirmation and contact emails stoped coming.
When running self testing i get:
" Sending test email to your contact form address: firstname.lastname@example.org from: email@example.com. Unable to send test email.
Exception message was: Incorrect authentication data
Please check the user guide for frequent error messages and their solutions.
Default templates exist.
Email communications are enabled.
Required database tables exist.
Testing failed, please review the reported problems and if you need further help visit the support page or contact me via firstname.lastname@example.org for support. "
in aschroder.smtp.log i get all the emails that users are trying to send....
In exception.log i find this: http://pastebin.com/F2s6ywjY
You received this message
"Exception message was: Incorrect authentication data"
You should insert again the email and password on SMTP PRO -> general settings