Yesterday tried to answer to an email from Microsoft's Hotmail/outlook.com. And of course my email was rejected because "part of [my provider's] network is on [Microsoft's] block list". So they are blocking emails from subnets when they notice there are any suspicious activities. Not based on my host's reputation that didn't change for the past 2 years.
Just if you search for a reason to switch to a another email provider.
Have you tried filling the Outlook.com delivery sender info form? I didn’t do it personally but I’ve seen people mentioning it:
@wiktor Good point.
I immediately felt in love with this form when noticing that it doesn't support IPv6…
@wiktor I just got my answer:
They can't see any problem for my IP address delivering emails to their services. Also they are happy to inform me that they have two programs that I can join in order to see the status of my IP reputation…
Right… I'll start to signup on every mail provider's webpage in order to get my mails delivered there… Fix your filters!
@sheogorath also using Netcup? Today I was unable to send mails to outlook.de and Microsoft was unable to figure out why my IP was blocked 🙄
@bjo yes, also using Netcup for my mail server. Maybe I should move it to Hetzner then 🤔
But something tells me that this won't solve the problem.
@sheogorath Some time ago I had a cloudbox at Hetzner in .fi and its IP was already on a blacklist. For the issue now, I could send using an 10 years old .org-domain, but not from a 2 days old .email domain. From the same server, so their error message is much more crap m(