Add the ability to have custom headers to the MailBuilder. The custom headers added to the Mailbuilder will be appended to the message headers within the MailProvider.
Unsure if this would be specific to all extensions of AbstractMailProvider or specifically to the SmtpMailProvider
Add the ability to have custom headers to the MailBuilder. The custom headers added to the Mailbuilder will be appended to the message headers within the MailProvider.
Unsure if this would be specific to all extensions of AbstractMailProvider or specifically to the SmtpMailProvider