I am trying to build a SMTP relay only in house.
this server will not receive mail from outside and will only be use by internal app / host to send email
It will not face public
i was thinking about sendmail / potbox but want to check if there is something light who can do the job correctly 
Hi Tom,
Yes but i am more looking for an in house solution.
But i will keep that one in mind
Thanks
Trying to send from an address provided by most consumer ISP’s probably won’t work as those are usually black listed in most spam filters.
What o/s? I am a big FreeBSD advocate and have a requirement for this quite a bit, one of the solutions we use for this is ssmtp.
I would suggest using Amazon Web Services Simple Email Service, it’s cheap ($0.10 per 1000 emails), uses standard SMTP transport, get spam reporting, and most importantly gets into most major mail providers inboxes.
Getting email into the inbox at major mail providers is difficult, because you must follow all the rules of preventing spam and it’s a lot to take in for someone that just want to send email as part of an application or service. Getting into Microsoft Outlook [formally Hotmail] accounts inboxes are extremely difficult, without using a smart host or mail relay provider. Gmail accounts easier, because at least they get to a spam folder, while Hotmail account just blackhole the message.
However, if you want to host your own mail server to send outgoing mail only there are a few options:
- Postfix (replacement for sendmail) very popular
- OpenSMTPd -Linux or BSD by the OpenBSD Team
- sendmail (Postfix is better)
Now for some guides on setting up a send only or a full mail server:
-
Postfix as Send-Only SMTP Server on Debian 10 (Digital Ocean)
Should work on Ubuntu - Workaround.org ISPmail Tutorial
- Ars Technica’s Your Own Email Server Series (Part 1, Part 2, Part 3, Part 4)
You will want to read the first three mostly for background, but part 2 is the section you need, disregard the Dovecot stuff - that’s for mailbox hosting. - Mail-in-a-box - I hear is good, but I chose the above options, this is a full mail server.
If you need mail sending for a web app, you may run into a spam filtering issue, because Postfix will send the email with the local address in the headers. So in most mail clients, the message appears to be from myapp@myappdomain.com, but the headers of the message says that its actually from www-data@server1.example.com (or worst www-data@Misty-Meerkat or other auto generated server name), which a spam filters add this a tick toward being spam.
If you are on Windows Server, there was a server role named POP3/IMAP or Mail Server (I haven’t used Windows server since Windows Server 2003), you could use that role to setup a mail server on Windows Server.
I hope this helped.
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