Hi, am I correct in understanding that if another plugin is configured to send emails out using it's own From Email and/or From Name, then WP Mail SMTP will not override that plugin's settings with its own From Email or From Name which I've defined on the WP Mail SMTP settings page?
As far as I can tell, this is the case, but I just wanted to check and make sure.
BTW, you might want to be aware that Google Apps also offers its own SMTP relay service to its paying customers, using a different SMTP server: it uses smtp-relay.gmail.com rather than smtp.gmail.com. This relaying service doesn't require SMTP Authentication at all (no username/password required) - rather, the Google Apps customer only needs to tell Google the IP addresses of the servers which will be sending through smtp-relay.gmail.com (eg. the WordPress website IP), and the emails obviously need to be using the customer's own domain name in the sender address, but because they are not using SMTP Auth, they are not actually sent "through" one of the Google Apps mailbox accounts. So the sender name/email are determined by the sending server, eg. the WordPress website in this case.
I've configured your plugin to use this service and it's working fine so far. I just set it to *not* use SMTP Auth and the emails generated by WordPress get relayed nicely through the Google Apps server, using the from name/email that the WordPress plugin (or core) determines.