Not so much 'bad service' as 'bad practices' (Laziness)
... I'm getting tired of not being able to email people just because I have a local copy of Postfix running on my OS X laptop. Apparently, ISPs don't even bother checking my mail to determine whether or not it is spam -- they just throw away/bounce my messages, which have CORRECT headers, NO hints of being spam, and are just small snippets meant to go to friends. I started this practice after another bit of bad service on the part of my employer's email system not letting me send work email from home despite knowing who I was! (They think we should use shitty Exchange webmail if we work from home or are traveling, and where I work that happens a lot. Yes, the system can handle SMTP-auth -- I did all the hard work of researching it for the network admin, as I do user desktop support so I know him well, and the lazy ass STILL won't fix it!)
So I set the system up so that I handled my own outgoing mail for ALL of my accounts, not trusting administrators to RTFM and do it RIGHT. Turns out my mistrust was justified.
"If you want things done right, do them yourself." Until they fuck it up ANYWAY!