Hi Bastian, On 16.03.19 11:28, Bastian Blank wrote:
> So your _provider_ is on the the MS blacklist. Netcup did not show up > on my radar, but I don't know what else. > >> Here's what I've checked/tried: >> * Neither I nor any of my users send spam. The mail volume is VERY low. > > It is really low, so low that DNSWL did not pick the IP up as recurrent > sender or refuse to. I wasn't aware of DNSWL before this, so I'm going to look into it for sure. Thanks for the pointer. >> * I use a reputable service provider for my server (i.e., I suspect if >> there were other customers in my IP range doing bad things, they'd be >> kicked out). > > Not according to the rejection by MS services. True. However, I don't understand why, even after whitelisting my server's IP it gets blacklisted again shortly thereafter. >> In my desparation I've even registered to the Google Postmaster thing >> and demeaningly "verified" my domain by altering the DNS: >> https://postmaster.google.com/ -- all data is entirely empty (even >> though there were positively mails blocked since I've registered with them). > > For the correct domains? I don't see any verification records for > spornkuller.de. Ah, I thought it would be sufficient to register the domain which the MX record points to (johannes-bauer.com in my case, which aliases with spornkuller.de). But I'll register spornkuller.de as well and see what I get. >> If anyone has any ideas of what could be wrong, I'm absolutely grasping >> for straws here. Any help is greatly appreciated. > > Let's point out the obvious(?): > > You MTA is known under different names: > >> johannes-bauer.com mail is handled by 10 johannes-bauer.com. >> spornkuller.de mail is handled by 10 spornkuller.de. Is this a problem? In other words, should I refer to the MTA always under the same name, i.e., have the MX record of johannes-bauer.com point to spornkuller.de? If this is somehow an issue I definitely overlooked it. > It does not advertise ESMTP (how the heck did you manage to > miss-configure it this much?): > > | % nc spornkuller.de 25 > | 220 Hi there Ugh! smtpd_banner = Hi there My best guess is that I was testing something and had it half-configured or whatever. I'm fairly sure that it was previously disclosing full version numbers and that's why I was poking around with that setting to avoid it. Fixed and thanks for the pointer. Is the banner however also used when Postfix connects to a different MTA? Because I only have problems delivering messages, no issues receiving at all. > Claim your info at dnswl.org. I will, thanks a bunch for the info. Your support is greatly appreciated! If we ever meet in person, please remind me and beers are on me :) All the best, Joe
