Big fan of Posteo here too. I’ve always found their customer support very responsive and helpful.
The only drawback for me is that they don’t support custom domains, which I can understand. I’ve yet to wrap my head round how I could use use a Posteo emal address alongside multiple aliases on a custom domain (perhaps using something like addy.io or similar).














I also have a Tuta account which is where I use my custom domain addresses (the number of aliases is unlimited there too, and I have so many!).
From what I’ve read, I’m not sure Posteo has a solution to this issue. I’ve read about a workaround, but also that it might have some issues.
But I do love Posteo for their stance on privacy and use of green energy, and the price is so reasonable. I’m thinking I might just have half a dozen or aliases there: one for mailing lists, one for online ordering, one for non-essential website logins and so on.