When sending emails from my main Optus email account som eof my reguar contacts are not receiving anything from me at all. Is something blocked? Could my IP address be blocked? Frustrating as I just can't tell who can receive from me! Thanks
Well you should get a bounced message if multiple contacts are getting blocked and in than bounced message it normally lists the offending IP address.
Depending on you internet connection just restarting your modem may aquire a different mail server and subsequently a different IP.
If that doesn't help, are you able to test sending those emails from a different connection? For example, if you're using your broadband service at home, can you try sending emails from your mobile instead? This will help isolate the root of the issue.