Not receiving email notifications from UTM any ideas?

Question

I receive notifications from all my commercial UTM setups OK because they are using static IP&rsquo;s. 
 However my home setup which uses on old SG120 with the home licence refuses to send me emails. 
 My home ISP uses dynamic IP&rsquo;s and therefore requires an external SMTP server to avoid the old spamhaus block. 
 Fine, no problem, I gave it an external SMTP server, a trusty simple 123-reg one but still no emails. 
 The SMTP log shows the server still trying to send emails itself and hitting the spamhaus default block. 
 
 I have tried different email addresses, different ports, TLS, no TLS, restarting the UTM. 
 I use this 123-reg account as an external SMTP server for several other devices without issue. Any ideas as to what may be going wrong?

kieranfame · Answer

Just to close this topic off, I have given up trying to get the UTM to use my smarthost or any smarthost in fact. Not sure why it isn't working, I've set a great many of these up over the years on all sorts of devices and never had this much trouble with such a simple thing. 
 I am, however, getting emails from the UTM. This is how... 
 1, I turned off the smarthost page 
 2, I had a lightbulb moment "since every email account server has a problem with my IP address, I wonder if one run by my ISP whitelists its own dynamic range" 
 3, Log into my ISP web admin and dust off that free email account they mentioned years ago. Setup a forward to my actual email. 
 4, Replace notification addresses and send as address with ISP email address. 
 5, It definitely does whitelist its own addresses. Success! 
 
 So there you go, completely obvious when you think about it but somehow I didn't think about it enough.