Callum Macdonald on "[Plugin: WP Mail SMTP] Send all WordPress emails via SMTP - Not working"

Try installing version 0.9.1, does the issue you're experiencing go away?
http://downloads.wordpress.org/plugin/wp-mail-smtp.0.9.1.zip

There were no changes to the logic, 0.9.2 and 0.9.3 were just bugfix releases. So upgrading shouldn't have broken any SMTP functionality.