I have upgraded to OS X 10.11.2 on my iBook and now cannot send emails from my Mail application. I receive emails but cannot send.
10.11 does not run on iBooks. You sure your notebook is called an iBook?
Apple made iBook notebooks through early 2006.
After then Apple named the consumer lineup of notebooks MacBook. Then later they introduced the MacBook Pro and Air.
iBook as a name returned only for the eBook format on iPads, iPhones, and Mac OS X 10.8 or later.
Go to the screen frame or the bottom of the computer chassis on the outside to find the name of the machine, or Apple menu -> About This Mac.
Mail will not send if your Apple menu -> System Preferences -> Internet Accounts is set different from your Mail menu -> Preferences -> Accounts, or the SMTP server is setup with the wrong port. At least that's how El Capitan works or doesn't.
It would help to know what email server you use. Is it an IMap or SMPT server.If you receive but can't send you outgoing is not configured right.. Here is something that may help. http://www.netregistry.com.au/support/apple-mail-os-x-tiger-10.4-email-setup-tut orial/ or.https://www.authsmtp.com/mac-mail/default-port.html
SMTP is sendmail only. POP and IMAP are the more popular receiving mail
I have upgraded to OS X 10.11.2 on my iBook and now cannot send emails from my Mail application. I receive emails but cannot send
