1y ago

[Abandoned all hope] Trying to self-hosting a mail server, but port 25 is blocked by my ISP

So, I spent the last few days researching and then finally setting up mailcow. I got my domain name, my wildcard certificate, got all the containers up, disabled ipv6 (I don't have it set up on my home router and am too lazy to set it up tbh), created a domain and an mailbox, etc.

Well, when testing it late last night, I found that I could receive mail but was getting timeouts when sending mail. After some googling, I found out that this will happen if port 25 is not open. Using traceroute, I found that port 25 traffic is not going outside my home network. And sure enough, I found on my ISP web site that I need to have a business account to unblock port 25, which costs twice what I am paying for internet now.

So what are my options? Is there any way around this? Do I need to host this elsewhere, such as AWS? Can I use a proxy or something that can translate it to a different port for me?

Edit: Yeah, so I just set up an alias to my existing email address. It isn't what I wanted to do, but as many have pointed out, I'm fighting a losing battle here. :(

21 comments

Pointless. Your selfhosted e-mail will just end up in spam-filters anyway.
Sadly email federation is on its last breath and you are better off using an external service somewhere if you want your email to actually reach anyone.
Edit: it's not much better on VPS you can rent either.
Edit: and in before the person that claims they have been self-hosting email for 20 years already... yes exactly! That is why yours still works.
- Edit: and in before the person that claims they have been self-hosting email for 20 years already… yes exactly! That is why yours still works.
  You're out of line, but you're right. Lol
- Why is this? I know my dad has self-hosted an email server for about 15 years, and he only recently started having issues with his email going to spam. He was able to get it worked out, but he said it was annoying af, and he didn't recommend getting into it now either. I think he had to talk to Google to get some special certificate or something.
  
  Well, your dad seems to have answered your question already no?
  Google and Microsoft are using spam as an convenient excuse to wall off their email gardens and to put insult to the injury, they are a major source of email spam these days.
- @poVoq I only in the last year or so set-up an SMTP server for outbound only. DKIM, SPF and DMARC configured. I never have issues sending email anywhere.
  
  They don't bounce when the spam filter catches them. I have seen many people claiming they have no issues sending emails just for all their emails directly go to the spam-folder in my gmail account (that I reluctantly have). Maybe ask the people you are sending the emails to? Just because you don't immediately notice the problem doesn't mean it isn't there.
  
  Try a delivery test to an Outlook / Exchange server. I'll be amazed if it goes through.

I can agree with everyone here, self hosting mail at this point is pointless. You are going to spend so much of your time reaching out to be pulled off of blacklists only to be added right back onto another. It’s a vicious cycle unfortunately, and than just wait until you get added to Barracudas or Proofpoints naughty list… you may as well start over at that point.

The major email providers will only handle email from know good and trusted IPs. If you’ve been hosting on the same IP for 15 years you’re trusted. If you started it last night your IP is still untrusted. It takes a long time to gain trust.
SendGrid has a good explanation here: https://sendgrid.com/resource/email-guide-ip-warm-up/

You can use a VPN or proxy but it's pretty much guaranteed that those IPs are already wildly abused and that your emails will go straight to spam.
At this point a VPS or cloud is indeed pretty much the best option and even then, you'll need to let it age up for a while because AWS's IPs are also wildly banned and give it some time to get unbanned and unban requests to go through.

I'll be repeating what's said already but coming from someone who hosts his own non critical email
VPS Either with a TCP reverse proxy back home comming in on an other port (seems most compatible with mailcow at home)
Or hosting postfix on the vps, you could still do IMAP at home

And sure enough, I found on my ISP web site that I need to have a business account to unblock port 25
This is very common, unfortunate you didn't realize it until now. The easiest solution to that is to upgrade your internet service to business class with static IP. But like the others said this may be futile being that all the major email providers are going to mark emails from your domain as spam (& in some cases null route those incoming emails), it takes a long time for all the major email providers to trust you.

You can use sendgrid to send your emails. That gets around the port 25 problem, but everyone is right - you’ll have a difficult time getting through spam filters even with them.
I selfhost my own email mainly so I don’t have to go through the Google unsecured apps rigamarole every time I want to set up smtp for one of my services, but no one except protonmail gets it reliably.

DON'T ABANDON HOPE! https://community.mailcow.email/d/1275-the-ultimate-guide-to-run-your-own-smtp-relay-server

It's possible but an archane mess of aspects to deal with. DMARK, DKIM, and SPF records are a pain to deal with.
That said, I have a pretty consistently working mailcow set up that doesn't need 25 (most home ISPs do block that because of spam bots taking over granny's computer) instead it uses 587 to relay messages through mailjet at no cost since it's only a few a month. I used another similar marketing relay before too, they all work similar. It does have the drawback of the relay having access to outgoing mail, but incoming is straight to me and not like any other online mail service couldn't just scan your entire mailbox at will.
Mostly used for internal system notices that dont leave local and signup valudations anyhow so there's not much for them to gain from it.

21 comments