For two months I've been using Optus email from within a different ISP not an issue in outlook 2013.
Now suddenly I'm now getting Server error: '554 5.7.1 <example@mail.com>: Relay access denied'.
I can send to my optus email account not a problem, I can still recieve emails but if I try to send outside the optus email path I get the above message.
If I log into the optus webmail it works fine but I can send from outlook.
I've checked my email settings which haven't changed in two months to make sure they are the same. Any help?