You can find the answer in #37 of this thread. "You can't, as any external server will try to connect your mailserver on that port. If your ISP has port 25 incoming closed, then you can not receive email on your own mail server with that internet connection." You want to run a mail server that is able to receive mail from the internet? Then either get your ISP to open port 25 or you must host your server in a datacenter (or get a VM e.g. from linode, and run your server there instead of hosting it at home).
Oh dear. @Quaxth most of your questions could be answered by a simple google query. I really don't know why @till is still so patient answering all the questions (mostly twice …, lucky you!).
You can run postfix on any (free) port. But nobody will try to connect to this custom port. When e.g, gmail tries to deliver an email to your server, then it will only use port 25 only. so changing the smtp port to 2525 will not help you with that problem.
And what's a bout a Relay Server? Those are SMTP Servers as well, could such be used? I mean in ISPConfig with my Domain! Thanks.
Relay servers are used for sending email. You can set a relay server under system > server config, if your ISP provides one to you. But you won't be able to receive any emails. To receive mails, you need a mail server that is able to get connections on port 25.
Thanks, Till. And sorry, I get a bit confused! For what are the POP3 and IMAP? Those are for to receive Mails on Port 110 (POP3) and 145 (Imap) in general, AFAIK. SMTP is used for to send mail in general and use Port 25. So, why I could not receive Mail on my server via, POP3 (port 110) and/or Imap (Port 145)? And use for to send a Relay Server (Port 25)? Thanks.
Please try to find an article on the internet that explains the basics of the internet email system. I will not start to teach you here the very basics on how the internet works. What you mix up here is server and client. A server does not receive any email through pop3 or IMAP. IMAP and POP3 are protocols used by an Email client to connect to a mail server and to fetch mails from there.
OK, thanks for the explanation. Tomorrow I'll check with my ISP again to get Port 25 to work on my IP, just the service I called some minutes again, told I've to pay some extra fees for that but know how much. Maybe I move my whole mails to a 3.party provider. Have to check what way is possible. Thanks for your patient and help. Good night.
OK, now the Mail is working with the standard ports 25 and 587: After I talked to my ISP today, they opened blocked Ports! I simply told them that I like to change the Service to a different company if I could not get blocked Ports opened! What they didn't will create, is the PTR Record, but the Mail seems to work now, so I'm OK for now! If same problems starts' again (sometimes?) I may have another solution for it, let see! Thanks for the help and patient!
I was getting a call from my ISP and they're offering a creation of a PTR Record for additional US$ 50 a month!! That's as "little" as US$ 600 a year, NO Thank you! The monthly income in Thailand is for normal people about THB 10,000.00 (or below US$ ~300.00)! So that costing is simply ridiculous! So, I'll test that Mail Server now for the next week and if that run well, I'll add the Production Domain to the server. Again, thanks for the help and patient so far!
A question: After I add a new Domain (TLD .com) to the ISPC, and I would use email service for that Domain with its exact Domain Name, I need to create the related A Records and an MX Record as well, I think, pointing to the Server with its full Server name server1.thaifw.us, is that correct? And emails to that domain (let name it example.com) like [email protected], will arrive correctly and be sending emails will show the [email protected] as sending Mail Server? Is that correct too? I think it is, just want to be sure. Thanks for the answer.
The mail server will work without PTR, but other mail servers might reject your email or mark it as spam. Yes. You need an A-record for the domain and probably www subdomain pointing to the server IP if you want to host the website and you need an MX record pointing to the server hostname. Personally, I won't host a server at home. You get nice and cheap virtual machines from e.g. Linode or Digitalocean for about 10 USD / month for a vserver with 2GB ram. Such a server has full internet connection, no closed ports, a reverse record for its IP. And the monthly expenses are probably below the electricity costs of running a server at home (at least if you run a normal x86 system 24/7).
Thanks for the answer. If that problem occurs, I maybe could bypass that with a Relay Server. I've bad experiences with that and that had cost me a lot of money too! I don't want to discuss that on the public, just to tell, it has to do with some Law in Thailand. On the other hand, if using a vserver, that run on shared servers and didn't give 100% control to the user, and that 100% control I need. And there also some limits which make the working with a shared server difficult, besides of the time consuming lower speeds for Up- and Downloads etc.! I'd use several Providers over the last few years, incl. Linode and Digitalocean and had a lot of problems with their limits and even down times, besides of other problems. The only solution would be an own physical Server in a Datacenter and that's too much expensive! That said, I'll carry on and use my own Server, at least for some time! Problems are facing are related to our Government, it makes many things very difficult! Even to simply register a .co.th Domain, is a PIA, and will have a lot of restrictions the user has to follow! Anyway, thanks a lot for your answer and advice, which seems to be Ok for Germany or Europe, but Thailand.
