Setup a Local Only SMTP Email Server (Linux, Unix, Mac)

Email Server (Linux, Unix, Mac).md

Setup a Local Only SMTP Email Server (Linux, Unix, Mac)

1 - Point localhost.com to your machine

Most of programs will not accept an email using just @localhost as domain. So, edit /etc/hosts file to make the domain localhost.com point to your machine, including this content to the file:

127.0.0.1 localhost.com

2 - Install Postfix

Fedora/CentOS/RHEL: sudo yum install postfix

Ubuntu: sudo apt-get install postfix

MacOSX: Postfix is already installed by default.

3 - Configure Postfix to Local only

• During postfix install process, the configure text dialog will display five options:

  General type of mail configuration: 
  
  No configuration
  Internet Site
  Internet with smarthost
  Satellite system
  Local only
  

• Select "Local Only".

• For the domain name, use the default suggested and finish the install.

4 - Configure a Catch-all Address

Enabling this, you can use any email address ending with "@localhost" or "@localhost.com".

Example: here, my unique account is [email protected]. But while testing systems, I can use any address like [email protected], [email protected], etc, because all will be redirected to [email protected]

• If not exists, create file /etc/postfix/virtual: sudo nano /etc/postfix/virtual
• Add the following 2 lines content, replacing <your-user> with your Unix user account:

@localhost <your-user>
@localhost.com <your-user>

• Save and close the file.
• Configure postifx to read this file:
  • Open /etc/postfix/main.cf: sudo nano /etc/postfix/main.cf
  • And check if this line is enabled, or add it if not exists: virtual_alias_maps = hash:/etc/postfix/virtual
• Activate it: sudo postmap /etc/postfix/virtual
• Reload postfix: sudo systemctl restart postfix
• If you're under non systemd distro, like Ubuntu 14.04, service restart command probably is: sudo service postfix reload

5 - Install Thunderbird

Ubuntu: sudo apt-get install thunderbird

6 - Configure Thunderbird

• Skip the welcome screen (click in the button to use existing accounts);
• Click in the Settings button at top right (similar to Chrome settings) then click on Preferences > Account Settings
• Under Account Actions choose "Add Other Account"
• Select "Unix Mailspool (Movemail)"
• Your account will be <your-user>@localhost (of course, replace <your-user> with your user account). Don't use <your-user>@(none), use <your-user>@localhost
• Ingoing and Outgoing server will be: localhost
• Restart (close and reopen) Thunderbird.

7 - Start your Mail Spool file

• This step have two purposes: test your install and stop the Unable to locate mail spool file. message.
• Using Thunderbird, send new email to <your-user>@localhost, replacing <your-user> with your user account
• Click on "Get Mail"
• Test catch-all: send new email to averagejoe@localhost
• Click on "Get Mail" and you'll see the message at Inbox.

The instructions are clear for Postfix, but current Thunderbird versions are fussy.
I'm on Ubuntu 20.04, with Thunderbird 78.11.0. netstat indicates that postfix is listening on port25.
But Thunderbird says it can't connect to the account for incoming messages
Thunderbid seemd to want to prepend a . to the server names: I assumed since that needs to be removed for the SMTP settings, the same should hold for the IMAP. Is there a combination of port and security settings that works?
143, connection security: none, password transmitted insecurely does not seem to work. Thunderbird is also not prompting for a password, but it doesn't react well to being told to remember an initial password either.

Thanks,
This is really good post !

thanks for the tutorial.
but I could not find the correct option in section 6 -> Select "Unix Mailspool (Movemail)"
it was only one option "Newsgroup account"
how could I fix this? thx in advance

-------Edit-------
for users who does not find the "unix mailspool" option sam as me:
thunderbird has removed the "unix mailspool" support since version 91. if want to follow this instruction, install a older verison instead

First, thanks for this tutorial:)

thanks for the tutorial. but I could not find the correct option in section 6 -> Select "Unix Mailspool (Movemail)" it was only one option "Newsgroup account" how could I fix this? thx in advance

-------Edit------- for users who does not find the "unix mailspool" option sam as me: thunderbird has removed the "unix mailspool" support since version 91. if want to follow this instruction, install a older verison instea

another option is to simply show the mail textfile in thunderbirds local folders.
Notice that this is no elegant version but it seems that unix movemail will not be supported in the future

1. Thunderbird: Right click on 'Local Folders' -> Settings. Copy your the 'Local Directory'-Path.
2. Close Thunderbird
3. Create a new Symlink via Terminal:
   NOTE: Eather escape the whitespace or keep your path (Local Directory) between quotation marks

ln -s /var/mail/<username> '<LOCAL DIRECTORY>'

5. Change Permissions for /var/mail/<username> to 666 or 600
6. You will find incoming mails in your Local Folders/'username'

Source: https://www.it-consulting-stahl.de/2022/06/zugriff-auf-lokale-mails-mit-thunderbird-91/

It appears that Thunderbird has plans to restore movemail someday in the future: https://bugzilla.mozilla.org/show_bug.cgi?id=1802145.

In this meanwhile, people is advising to use BetterBird.

Since Unix Mailspool was removed in Thunderbird, a really great option is to install Betterbird 102.8.0-bb30 (14 February 2023). It is a much better implementation of Thunderbird that allows local mail.

https://www.betterbird.eu/

but im using just a server without a gui how can i do the step 6****

got stuck on step 6, managed to get through it by installing Thunderbird version 45 (cause this tutorial was created around time version 45 was used).

Hi,
I am surprised that you are accessing emails from Postfix email server via Thunderbird client without installing Dovecot or Courier-IMAP which let the server listen on port 143 (IMAP) and 995 (POP3). The server is listening only port 25 (SMTP) with your configuration. I think it is an incomplete tutorial.

@1egend78 This is a tutorial only for development testing purposes on localhost. It's not intended to be a real email server. In this sense (be a real email server), yes, it's missing other steps.