Changing the "Sender" in site emails from SiteName?

We're optimizing our site for SEO and one of the tips is to make the site title of the site more search engine friendly:

"My site name" becomes "Keyword rich description of my site content - Site Name"

This is fantastic for SEO ratings, however, we're running into a problem where Dolphin is pulling the site title as SiteName for the sender name in outgoing emails. We've edited all occurrences of <SiteName> in the email templates, but the sender is still showing up as  "Keyword rich description of my site content - Site Name"- which we do not want.

Does anyone know where to find the code or database instance where I can change the sender of site emails from <SiteName> to my actual site name? 

You can use SMTP mailer to send mails, there is an option to override sender's email and name.

Thanks, that worked!

Ok, revising the "that worked" response.... it worked to change the name of the sender in some emails but not all (even though all of the templates were updated to remove all site title references) and, even worse, the formatting is lost. For example the birthday email that is formatted to send a birthday graphic with a nice message is actually being sent with just this as the content:

/*Happy

Suggestions?

It works with every email template which uses standard Dolphin sendMail function. As I know Dolphin using this function everywhere. Please can you specify what emails exactly are sent using wrong sender name ?

Also It maybe that some module uses other methods to send mail, or using it incorrectly. Then I suggest to contact author and ask to update the modification/module and use Dolphin sendMail function to send any email messages or fix the problem.