After sending an email with an attached photo, this message was displayed on my computer:
host smtp.secureserver.net [126.96.36.199]
SMTP error from remote mail server after RCPT TO:<firstname.lastname@example.org>:
550 5.1.1 188.8.131.52 is not allowed to send from <haydendrills.com> per it's SPF Record. Please inspect your SPF settings, and try again. IB508 <http://x.co/srbounce>
Reporting-MTA: dns; hosting06.net.firstcomm.com
It is referring to my SPF settings which is new to me. I also tried sending the same message from my iPhone and did not receive any error message back, so that seems OK. I copied the iPhone password for the Exchange Office365 account on to my work computer to make sure they are the same. I do have an old computer at the office running OS X, version 10.5.8 and Mail version 3.6 but have had few problems up to now. I don't see any reference to SPF settings in Mail. Messages sent without an attachment seem go through OK. Anybody have any ideas?