Is setting up my own SMTP server to send email a waste of time with regards to deliverability?

Question

I have a dedicated host serving a few domains I manage. I host my own email and IMAP server.

The server is at buildoneforme.com with IP address 144.76.81.247. I think reverse DNS is working:

$ host 144.76.81.247
247.81.76.144.in-addr.arpa domain name pointer buildoneforme.com.

I also run a community group with its own domain name and website (hosted on the same machine), and I'd like to run a mailman discussion list with a few hundred members.

I have set up my MTA (exim4) to send email, but I'm experiencing deliverability problems, specifically to Microsoft (e.g. hotmail.com, outlook.com).

Initially Microsoft blocked my IP address altogether, but I used a form to request that it be unblocked and my request was granted.

However, I now find that every email I send from this server is automatically put into the junk folder.

I have only sent a few test emails, no mailing list or bulk emails yet, and I've sent it to only 2 Microsoft test addresses.

I have done all the following:

• Joined Junk Mail Reporting Program
• Joined Smart Network Data Services program
• SPF
• DKIM
• DMARC
• TLS is available
• No open relay (I have to authenticate to send mail via TLS)

• Sent test email to [email protected] with the following result:

  SPF check:          pass
  DomainKeys check:   neutral
  DKIM check:         pass
  Sender-ID check:    pass
  SpamAssassin check: ham
  

I wrote to Microsoft to ask them to stop automatically marking all email from this IP address as spam, but I got a standard response including the following:

Unfortunately, after reviewing the information you provided and in compliance with our mail policies, we are unable to offer immediate mitigation for your deliverability issue. However, we have some specific recommendations for you to consider that can help you to improve deliverability over time.

This is followed by some generic recommendations which don't apply to me.

So my question is this: is it pretty much hopeless for a small operator like me to achieve good email deliverability using my own sending SMTP server? Should I just start using a 3rd-party service, like Amazon SES?

If I create lots of fake hotmail accounts and start sending to them, and then marking all mail as non-junk, will that help whitelist this IP address?

The only potential problem I can find with my setup is that I'm sending mail from a top-level domain, rather than a sub-domain, e.g. my server advertises itself as buildoneforme.com, not mail.buildoneforme.com, and the mx record is mail.buildoneforme.com (which points to the same IP address). Would this make much of a difference?

Solution 1

I've been running my own email server for 17 years, including hosting a large mailing list, and although it takes time I find it's perfectly possible, even today.

Most of what should be done, you're already doing; but one factor you don't address is what kind of IP address you're using. Many mail providers outright blacklist (or use as a strong marker for spam) IP address blocks which traditionally act as spam sources. First and foremost, those have been the domestic broadband address blocks, which if directly sending email are almost always part of zombie botnets. But in this case I note that your server has a Hetzner address, and is therefore very likely a VPS:

[me@anni ~]% whois 144.76.81.247
[...]
inetnum:        144.76.0.0 - 144.76.255.255
netname:        HETZNER-RZ-BLK-ERX1

VPSes are disposable, and a perfect target for senders who want to fire up a server to send out a couple of hundred million spams then disappear again. I imagine that at least some big providers have taken to adding VPS blocks to those internal marker/black lists.

My mail server is a physical box, painfully and expensively hosted at a colo facility, and possessed of some IP addresses from a range reserved for real server colo (or, more precisely: a range not known to be used for domestic or VPS purposes). These are much less likely to be regarded as structurally tainted, because it's much more trouble and expense to set up a physical server than a VPS, so a spammer is much less likely to do it.

So I guess my precise answer would be that it's still perfectly possible to run your own SMTP server, but it may require more pain than you have yet undergone. Sorry.

Solution 2

Don't give up hope completely. Running your own mail server is sometimes a pain but it sounds like you're doing everything right.

Generally I would say if they aren't blocking you outright (i.e. you get bounces back) then it's a content issue. Try adjusting the content somewhat. Microsoft aren't the best at anti-spam but they try hard for their users - sometimes too hard. Tell your users to whitelist you - add you to their address book is the usual way to do this.

Also make sure your mailing list software isn't setting your content as Precedence: junk/bulk. That might cause you problems.

Unfortunately none of this stuff is easy. Deliverability is a bitch. Mostly it is trial and error.

Comments

[Jenny D]

Seconded. Your IP address is one of the most important things a major email provider uses to block emails; if you're with a provider or in a netblock known to harbor spammers, you can kiss deliverability goodbye.

[user7406]

Thanks MadHatter. My machine is a dedicated host, not a VPS, but it's possible that the IP used to belong to one or more VPSs (or a dedicated machine used for spam).

[user7406]

Thanks Matt. In my case, the content is very simple. I've only sent a few plain text emails for testing. No bulk or mailing list email yet.

[MadHatter]

Fair enough! It's possible that some people think that Hetzner has a bad reputation, or I may well be wrong. I note that you've asked four questions, but accepted the answers for none. Local etiquette is that, when you're happy with the an answer to a question, you accept it by clicking the "tick" outline next to it. This drives the reputation system for both you and the answer's author, and stops the question floating around forever like a querulous albatross. My apologies if you already know this.