> If so, were you able to successfully communicate with and/or reasonably work through whatever issue got you black-holed?
Yes. Practically all black-lists have a de-list form that one can use, and most seem to auto-delist fairly fast as soon they don't get any more reports from honey-trap and other sources.
We do have a few custom written ways to detect hacked accounts, and we don't allow users to set their own passwords. We also tend to discourage/deny users who do newsletters and other "higher risk" form of email. All emails sent by websites is sent through different servers, which also mean that a hacked website does not impact the reputation of the email servers.
Events with black lists maybe occur once a year and as I mentioned above, fixed fairly fast. One good tip is to keep an automated eye on the mail queue and react quickly when things start to look wrong.
There are a few sites where you can plug in an IP address to see if it's on any blacklists. A handy thing to do before setting up a new server is to work with your provider to find a clean IP address beforehand. Here's one that I have used: https://mxtoolbox.com/blacklists.aspx
Now I have incentive, this is annoying. Maybe I need a static IP as well.
Yes. Twice.
In the first case, the mail provider was our ISP; and they got themselves in some mainstream blacklists. The problems getting that sorted out were part of the motivation for bringing mail in-house.
In the second case, there was some academic departmental mailserver and they were using some list incorrectly; using an extremely-opinionated list to block when it should at best be used to score.
This wasn't in itself a big deal, but one of my boss's correspondents was a senior professor in this department and they had some important business; and the postmaster was a dick, and wouldn't help. Boss didn't want to use some secondary email address; I had to show him how to set up an alias on some commercial server, which was second-best, but he was in a hurry.
Boss was angry with me and barked at me. If you run a mailserver for some group, one you assembled yourself, then people expect you to take responsibility for sorting out any mail problems. Well, they're right: you have taken on that responsibility. You made it, and you're running it: who else can they complain to?
[Edit] My point is that it's not hard to set up an artisan mail system; what's hard is that you create a job for yourself that is at the same time networking, user-facing, and technical. It's an interesting learning point, and I recommend it. But don't underestimate what you are taking on.
This. So much this.
I will happily run my "artisinal" mail system for myself. Would I put customers on it? Oh, hell, no.
I, sadly, always recommend that companies pay money to Microsoft for email. You are really paying for the customer support service rather than the email service.
Customers still have problems occasionally _sending_ email to one domain, which is over 15 years old and sends <1 email per day. If they initiate and email us we can't send them a reply (if they're on MS email, sometimes). We use an outlook.com email nowadays as a relay and have to treat MS using customers differently still despite using a relatively large supplier.
Some years ago, I was lead to believe, you could pay a third-party to add you to what was effectively MS's whitelist.
Aside: back then I was doing some webdev and supporting IE5+ so I already hated MS about as much as one could.
Never paying to enable interoperability that is part of being a reasonable web citizen/company. Paying them just reinforces the negative behaviour.
There are plenty of other email providers which are worth considering, and I'm sure some of them have half-decent customer support.
You would, sadly, be wrong.
Microsoft customer support is "least bad" among the email providers.
That is a massive indictment of email providers, but it is what it is.
Assuming logic applies to humans is painfully wrong. I wish it wasn’t.
I haven't administered e-mail servers for 20 years, but back when I did, this started to be a problem that eventually became insurmountable. I used to manage a small business oriented ISP. We were multi-homed with a /18 that we used for everything. I had a customer that was a reasonably sized organization that dealt with tourism and conventions for a major city. On one of their websites, (which we hosted with IPs that came out of the same /18 as their mail server,) they had a directory of vendors who were associated with them. ONE of those members had a website that had been hacked/defaced. This got our entire /18 on a blac-khole list. They had an employee that was trying to send e-mail to someone on a system that was using this black-hole server to filter spam.
When we explained to them what the problem was, we got glassy-eyed stares back at us and a, "just fix it." I told them that, they would need to remove the link to their partner's site from their website in order to get them AND all of our other customers using numbers inside our /18 de-listed from this particular black-hole. They asked, "We have hundreds of partners who pay for membership in our organization and being listed on our website is one of the benefits. How can we possibly police every one of those websites every day to make sure there's no defacement or serving of any problematic material from any URL in any of those domains?" That's a decent argument in my opinion. And I tried to explain that different black-holes have different policies and no black-hole is demanding that anyone use their system for filtering. I tired contacting the organization that was using that black-hole to explain the situation to them, but they weren't interested in discussing it. As far as they were concerned it was our problem to deal with.
This kind of problem happened dozens of times with varying degrees of severity but with increasing regularity and it was one of the primary reasons we quit hosting e-mail and started re-selling another vendor's solution. That was a long time ago, and maybe black-hole lists aren't a thing anymore.