使用Android帐户凭据发送电子邮件

I'm looking into building an email client for Android, and I noticed that the default Email app on android can use an account on the device to get email credentials. For an exchange email account I was able to get it connected with the Android account system, but not with K-9 mail. The default app now works fine as a client, but is really clunky. I've been looking though the source code of AndroidMail and MailActivity, but I haven't had much luck finding anything relevant to that. My goal is to let users connect their email accounts using the Android accounts system, and then use that account in the email client. Is this possible?I'm looking into building an email client for A