[GTALUG] Spamhaus block

[Marc Lijour]

Does anyone has insights about dealing with Spamhaus?

I'm getting increasingly frustrated by being listed without explanation. 
I run a very low bandwidth mail server and a website for my business. I 
am running postfix with SPF, DKIM, and DMARC. I'd like to know what I am 
missing.

Spamhaus is very popular which in turn affects Twitter, LInkedIn, beyond 
just the mail.

Is it possible to run one's own mail server this days?