Mail relay via Postfix [noob]

[eN0ch]

I'm hoping this is the right forum for this. My geekery is limited, so please minimise the geek-speak .

So I'm experimenting with a Postfix mail server on my home desktop mac. I'm not IT trained but I do enjoy exploring stuff. In other words it's a hobby. If it doesn't work out it's no big deal really. My setup is pretty low level. I'm not receiving mail through my server; only sending. Or rather, I send everything through an SMTP provider as relayhost.

The server's going great within the LAN. Love the speed. What's not going at all great is relaying mail through the server from outside the local network. I just can't get it to work no matter what settings I try. In all likelihood having a dynamic IP won't be helping. But I am running a DDNS (and the IP rarely changes). And if I telnet either to my current IP or to my DDNS hostname, it resolves quickly to the subdomain I'm using for the mail server. The telnet also confirms that my port forwarding is working.

The problem part is configuring outgoing mail settings in my email client. (Mail on mac and also iOS). I add a new SMTP hostname (I've tried both my mail server subdomain and my DDNS hostname). I enter the SASL username and password I have configured in Postfix. It seems to work at first, but after maybe 20 seconds the new server is marked as "(Offline)". And so it remains. I can never get past that point.

Can anyone give me some pointers? Thanks.

 

[satcomer]

This all depends, is pop email server or an imap server?

 

[eN0ch]

This all depends, is pop email server or an imap server?

Thanks. Neither. I'm continuing to get incoming mail from my mail provider (iCloud). The server I've setup is SMTP only.

 

[satcomer]

OK it's a Mail iCloud problem! Well there is the Apple Support document iCloud Mail Server Settings! SMTP is send part your having problems? I need to ask what version of Mac OS you running because it has changed in current versions of Mac OS! so tell me the version you running for a answer because how different it is in current version!

 

[eN0ch]

OK it's a Mail iCloud problem! Well there is the Apple Support document iCloud Mail Server Settings! SMTP is send part your having problems? I need to ask what version of Mac OS you running because it has changed in current versions of Mac OS! so tell me the version you running for a answer because how different it is in current version!

OK, thanks for staying on the case with me . I'm running Monterey (12.6.2). I'm surprised to think that this is an iCloud issue. But then that probably just marks me out as the noob I am 😂

 

[satcomer]

OK this might sou d funny but if I remember in older Mac OS you can change then in System Preferences yes->iCloud pane! you can change them correct there is remember rightly!

 

[eN0ch]

Nothing like that in the current OS, is there?

 

[satcomer]

Nothing like that in the current OS, is there?

in the 13.1 version it in System Presences->In Internet Account, iCloud to setup custom iCloud domains in iCloud.com!

Plus according to web site https://postmail.invotes.com/ they are having problems right now and as user you have to contact them!

 

[eN0ch]

Plus according to web site https://postmail.invotes.com/ they are having problems right now and as user you have to contact them!

Sorry, I'm not clear what that has to do with my setup. The problems mentioned there date to 2018. And have you confused Postmail with Postfix?

in the 13.1 version it in System Presences->In Internet Account, iCloud to setup custom iCloud domains in iCloud.com!

Sure. But I'm way past that stage. I've had my custom domain setup and running under iCloud for several months.

 

[Brian33]

The problem part is configuring outgoing mail settings in my email client. (Mail on mac and also iOS). I add a new SMTP hostname (I've tried both my mail server subdomain and my DDNS hostname). I enter the SASL username and password I have configured in Postfix. It seems to work at first, but after maybe 20 seconds the new server is marked as "(Offline)". And so it remains. I can never get past that point.

This sounds familiar to me. My family uses our own registered domain name for our email addresses. My incoming mail handler (pobox.com) actually just forwards mail for our addresses to our icloud mail addresses, which we keep private. No problem there. The other part is to have all outgoing mail with From and Reply-To addresses specifying our domain name (not iCloud). (Thus I can change my mail providers at any time without changing telling all my contacts -- they continue to use, and see, my domain name.)

So we use icloud's IMAP server and pobox.com's SMTP server. But IIRC it was really frustrating to get Mail.app on macOS and iOS configured this way. It was possible (it's been working for years) -- but it was not "the easy path."

I really don't remember what the magic formula was; all I can say is that it should be possible. I'm looking at my SMTP sever settings, and the only thing I notice is that the User Name field is my full email address (that is, the domain part is included).

Since your SMTP server is on your local network, I think you should be using your local name for it in the Host Name field, not using your DDNS hostname (I'm assuming your SMTP server is not accessible from the internet). Hmmm, just notice that the SMTP Host Name appears in two places: in the "Outgoing Mail Server" section for the account, and also in the SMTP Server List. I have the exact same hostname in those two places.

Wish I had a better advice for ya. Good luck, though!

 

[Brian33]

I've had my custom domain setup and running under iCloud for several months.

Oh, just now noticed this. I set up long before iCloud had that feature, so my domain is not set up with iCloud. So I'm not sure how that works -- my experience may not be relevant to your issue.

 

[eN0ch]

Oh, just now noticed this. I set up long before iCloud had that feature, so my domain is not set up with iCloud. So I'm not sure how that works -- my experience may not be relevant to your issue.

Thanks for taking the trouble anyway, Brian. I'm of course a few weeks progressed with this now. To clarify one aspect of my setup - we're doing something similar to your use of pobox.com. The one we use is smtp2go, which has been brilliant. So although I'm using my local server to send emails, no email I send goes straight to the big dark internet. It's 100% relayed through the SMTP service. I presume your setup is the same in that respect?

The iCloud custom domain feature is going great for us. We're among the Google Workspace refugee stream, after they shut down the free version. That was what led us to iCloud.

I now have a setup that allows me to send email through the local server from anywhere. Possibly the most interesting part of the journey was discovering Tailscale . People are calling it a game changer, and I can understand why. Courtesy thereof all my email sending from anywhere (not just home) is 'local', with no SSL or authentication settings in the client app, and all on port 25. Am I completely mad? I'd have said so a month ago. But Tailscale really is that good.

 

[Brian33]

Glad you got things working!

I've read positive postings about Tailscale in the past. It looks really cool. I don't really have a need for it, though it might be fun for me to tinker with their free plan sometime.